Le copie ovvero le versioni de “La Gioconda” a confronto: valutazione storico-artistica e diagnostico-analitica
10.6092/issn.1973-9494/6168
Lo studio storico-artistico e tecnico-analitico ha riguardato il confronto di alcune opere d’arte eseguite da diversi autori nel corso degli anni, il cui soggetto si riferisce e riprende la “Monna Lisa” di Leonardo. Al riguardo è necessario distinguere le due versioni di “Monna Lisa” di Isleworth e di “Monna Lisa” del Louvre, entrambe opere di Leonardo da lui eseguite in periodi diversi, dalle copie di una o dell’altra versione o di una combinazione di entrambe.
application/pdf
1973-9494
6168
en
Andrea Natali
Conservation Science in Cultural Heritage
copies
Mona Lisa: A Comparative Evaluation of the Different Versions and Their Copies
Text.Serial.Journal
https://conservation-science.unibo.it/
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Articles
2015-12-30
2016-05-27
2015-12-30
2018-03-27
57-109
CSCH
Andrea Natali
2015/12/30
10.6092/issn.1973-9494/6168
57
University of Bologna
1973-9494
copies
en
109
LARRY K., ROY A., MORRISON R., SCHADE P., 2011, Leonardo da Vinci’s Virgin of the Rocks: Treatment, Technique and Display, National Gallery Technical Bulletin, n.32
Mona Lisa: A Comparative Evaluation of the Different Versions and Their Copies
https://conservation-science.unibo.it/article/download/6168/5937
15
M     ONA LISA: A COMPARATIVE EVALUATION OF THE
      DIFFERENT VERSIONS AND THEIR COPIES

    Salvatore Lorusso*
    Dipartimento di Beni Culturali
    Alma Mater Studiorum Università di Bologna, Ravenna, Italy

    Andrea Natali
    Dipartimento di Beni Culturali
    Alma Mater Studiorum Università di Bologna, Ravenna, Italy


   Keywords: “Mona Lisa”, versions, copies


   1. Introduction

   In a previous study [1], which included stylistic and diagnostic analyses, it was found
that the oil painting on canvas “Mona Lisa with columns”, part of a private collection
in a museum in St. Petersburg (Figure 1), is a copy of the “Mona Lisa” by Leonardo
(Figure 2) dating to a period between 1590 and 1660. Noteworthy features include the
good quality, readability and expressiveness emanating from the work, which presum-
ably is of Nordic influence, specifically German-Flemish.




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Figure 1. Photograph in the visible of the painting “Mona Lisa with Columns”, St. Petersburg (oil
on canvas 63.2 x 85.2 cm )


* Corresponding author: salvatore.lorusso@unibo.it

                                                                                                    57
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         Figure 2. The Louvre “Mona Lisa”

                                                                                            More specifically, given the importance of the subject, which includes Leonardo’s
                                                                                         well-known masterpiece, the conclusion that was reached in defining the above paint-
                                                                                         ing a copy of the original, involved examining, from a methodological point of view,
                                                                                         investigations carried out in 2004 on the Louvre “Mona Lisa” by the “Center for Re-
                                                                                         search and Restoration of the Museums of France”, and published in “Au coeur de La
                                                                                         Joconde – Léonard de Vinci Décodé”. This sequence of investigations – which were
                                                                                         certainly not aimed at authentication – were examined together with those of the Na-
                                                                                         tional Gallery in London, thus enabling comparisons to be made with other works by
                                                                                         Leonardo [2-3].
                                                                                            The use of scientific methods has made it possible to provide a reliable answer in
                                                                                         the comparison made with what scholars have reported.
                                                                                            The present paper examines and compares a number of the many works depicting
                                                                                         the same subject. The works were chosen on the basis of their acknowledged artistic
                                                                                         quality and a series of technical data obtained by consulting diagnostic-analytical tests
                                                                                         carried out by several laboratories.
                                                                                            The comparison not only has the purpose of highlighting the particular presence of
                                                                                         the columns in the painting already examined, but also that of pointing out how, as a
                                                                                         result of the marked and widespread attractiveness exercised by Leonardo’s originality
                                                                                         through the years, on various authors, the various works, even if well-executed, never-
                                                                                         theless present some significant differences and particularities in the iconography and
                                                                                         / or technique employed.



                                                                                    58
   2. The “Mona Lisa” copies

   There are numerous copies of the “Mona Lisa”: some of good quality and others of
inferior quality. Among those worthy of note are, those in the Hermitage in St. Peters-
burg, the Walker Art Gallery in Liverpool, the private copy known as the Vernon “Mona
Lisa” in the United States, one in the collection of the Earl of Wemyss in the UK, and
another in Salzburg. Of particular significance is the Isleworth “Mona Lisa” – which
will be discussed later – depicting, between the columns, a younger figure than that of
the Louvre, but whose pose is similar. This painting is currently being studied by the
scientific community, as it is believed that it could be another autograph version by the
Master, from which other copies have drawn inspiration. There are in fact, copies with
a landscape similar to the Isleworth version, including that in Oslo, which have been
attributed to Joos van Cleve, Gabriel Ferrier and other authors. Other interesting cop-
ies can be found in the Alte Pinakothek in Munich, Germany, the Luchner Collection in
Innsbruck, and the Musée des Beaux-Arts in Tours.
   In 1952, on the occasion of the 500th anniversary of the birth of Leonardo, an official
count identified 61 works [4].
   It is, however, likely that other copies have been added to this number over the years.
Leonardo’s work has been studied in great detail: the particular characteristics of the
Master, his brushwork, composition, structure. The degree of innovation that charac-
terizes his work is the result of an extraordinary talent, praised by poets and writers of
the time, and from which stems the uniqueness of his production [5].
   However, from among the various copies, through careful archival and bibliographic
research, it was possible to collect data on only 13 copies: for some, only a small
amount of technical and historical data was available, for others, more in-depth study
was possible [6].
   In order to highlight the differences and similarities in the production of the various
copies of the “Mona Lisa”, three case studies were examined: the Prado “Mona Lisa”,




                                                                                                   CONSERVATION SCIENCE IN CULTURAL HERITAGE
the Reynolds “Mona Lisa” and the Isleworth version. The latter is considered by some
scholars to be an earlier version by Leonardo, in other words, a version produced be-
fore the Louvre “Mona Lisa”.
   Owing to their differences, the following three cases provide us with a significant,
but not exhaustive, informative picture of this art work.


   3. The Prado “Mona Lisa”

   3.1.Historical anamnesis

    The Prado “Mona Lisa” (Figure 3), is an oil painting on wood, probably produced at
the beginning of the sixteenth century.
    Reference is made to this interesting portrait for the first time in the 1666 inventory
of the Gallery of the Mediodia del Alcazar as’ mujer de mano de Leonardo Abince’. The
painting differs from other copies in a striking way.
    In January 2012 it underwent major restoration. The results led to a surprising dis-
closure: the black background hid a landscape and a parapet flanked by column bases
similar to those of the “Mona Lisa” in the Louvre. Furthermore, infrared reflectography
highlighted the similarity of the preparatory drawing of the copy with the portrait in the


                                                                                              59
                                                                                         Louvre. These results, together with the excellent state of conservation, show the origi-
                                                                                         nal colors of the Prado painting. However, there is no substantial evidence that Leon-
                                                                                         ardo himself used a palette similar to the version now in the Louvre. The two portraits,
                                                                                         therefore, are very different and were executed on panels of wood from different trees.
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         Figure 3. The Prado “Mona Lisa”

                                                                                            Information provided by the Prado Museum in 2010, has supported the belief that
                                                                                         the portrait was probably executed before Leonardo left Italy for France, which would
                                                                                         mean that it was probably painted in Rome around 1516. In fact there has never been
                                                                                         any hypothesis that the copy in the Prado was painted by Leonardo. Bruno Mottin,
                                                                                         head curator at the Center for Research and Restoration of the Museums of France,
                                                                                         has suggested that the painting could be attributed to one of Leonardo’s favourite ap-
                                                                                         prentices, perhaps Salai or Melzi. But it is also true that neither Salai possessed the
                                                                                         talent to paint such a lifelike picture, nor could Melzi have produced such a painting,
                                                                                         since he was only 15 when he met Leonardo in 1506, and was therefore too inexperi-
                                                                                         enced to paint this copy. On the other hand, if we assume that the painting is by Melzi
                                                                                         after completion of his apprenticeship and as an artist in his own right, it should have
                                                                                         been painted a few years after Leonardo’s death. A further theory is that the painting
                                                                                         was done by one of Leonardo’s Spanish pupils: in this case the painting may have
                                                                                         been completed in Spain. Another theory regarding the present location of the work is
                                                                                         that the painting was taken by the Spaniards when they sacked Rome in 1527.
                                                                                            However, in a press release issued by the Prado in February 2012, it states that:
                                                                                         “Following its rediscovery, this copy of the “Mona Lisa” in the Prado Museum, which
                                                                                         has now been confirmed as a work by one of Leonardo’s pupils or followers working
                                                                                         in his studio while the original was being painted, has not only been confirmed as the
                                                                                         oldest known copy of this enigmatic image, but also acquires considerable importance
                                                                                         for its potential to cast more light on the Louvre painting.”


                                                                                    60
    At about the same time, conservators at the Louvre announced the re-dating of
their “Mona Lisa” to a period from 1503-1519. The reason for this decision is unclear.
Of course, if, as the Prado scientists have theorized, the copy in Spain was painted by
someone who “... sitting next to Leonardo da Vinci, was trying to duplicate his every
brush stroke”, it would have meant that this artist stayed with Leonardo for 16 years,
a period when in fact, the Master alternated his work and travels between Florence
and Milan, and Rome and France, and only rarely put his hand to the painting, a quite
unlikely situation.
    It is moreover known that Leonardo had already suffered from a stroke in 1514,
while in Rome. In fact, when Cardinal Luigi d’Aragona visited him in 1517, the cardi-
nal’s secretary and diarist, Canon Antonio de Beatis, reported that “... nothing good
can be expected from his paintbrush as he suffers from a paralysis in his right hand.”
Leonardo was known to be left-handed, but at the time was over 65 years of age and,
naturally, debilitated. In addition, de Beatis reported that the portrait of the “Florentine
woman,” now considered to be the painting the “Mona Lisa” in the Louvre, was “quite
perfect”, in other words, completed. All these documented reports exclude the possibil-
ity that the ‘Louvre version was completed’ in the year of Leonardo’s death, in 1519.
    Perhaps the main argument that highlights the non-contemporaneity of the Prado
copy with the “Mona Lisa” in the Louvre, is that the two women are physically different:
the woman in the Prado is significantly younger than the Parisian “Mona Lisa”, and
has a more robust appearance, the hairstyle is curlier and more intricate, and the fin-
gers of her right hand, which are slimmer and longer, have been beautifully rendered.
Although the qualitative representation of the embroidery pattern is simplified, it is evi-
dent that to paint the face, hands and clothing with such finesse, must have required
more than just the experience of a student.
    The landscape is in some way incomplete and reproduces some of the intermedi-
ate layers of Leonardo’s original landscape, as revealed by the infrared photography
of the original. This suggests that the copyist stopped working before the original was




                                                                                                    CONSERVATION SCIENCE IN CULTURAL HERITAGE
finished. Leonardo then continued to work on the original version, which remained
incomplete [7-8].

   3.2. Analytical-diagnostic investigations

    Investigations of the Prado “Mona Lisa” were carried out in a joint collaboration
between the Prado and the Louvre in February 2012, in order to ascertain, distinguish
and describe the constituent materials, and to highlight the original compositional and
conservative procedures. The work has undergone invasive restoration a great many
times over the centuries, including transfer of the painting from a wooden support to
a textile one [9]. Analyses carried out during its last restoration led to the discovery of
the original painting, an extremely important aspect in understanding the methodol-
ogy employed for depicting light, in Leonardo’s workshop (Figure 4). This is the most
important copy of the “Mona Lisa” known today.
    The comparison of the Prado painting with that of the Louvre, together with techni-
cal documentation, have further contributed to a better understanding of the painting
in the Louvre and to completing the sequence of known phases in its execution. The
higher resolution of the images produced during investigation of the Prado copy, re-
vealed features of the original which had previously remained undetected. In addition,
data resulting from the comparative investigation of the two works has confirmed what


                                                                                               61
                                                                                         was already known about the way in which Leonardo’s workshop operated. A descrip-
                                                                                         tion is given by Martin Kemp in his research on the existing versions of the “Madonna
                                                                                         of the Yarnwinder”, but already indicated in a letter from Brother Pietro di Novellara to
                                                                                         Isabella d’Este after the former had visited Leonardo’s workshop. In his letter, Brother
                                                                                         Pietro claims to have seen two apprentices painting copies while the Master was busy
                                                                                         with other matters.
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         Figure 4. The Prado “Mona Lisa” before and after restoration

                                                                                             The existence of a landscape beneath the black background was revealed by in-
                                                                                         frared reflectography and examination of the surface in raking light before restoration.
                                                                                         This was subsequently confirmed by X-ray. Even with these tests however, it was nec-
                                                                                         essary to determine whether the black substance had been added after completion of
                                                                                         the painting, and if so, if it had caused any damage [7].
                                                                                             The dark background proved to be a re-varnishing done after 1750, using linseed
                                                                                         oil as a binder.
                                                                                             The landscape beneath the coating of dark color, was well preserved but not com-
                                                                                         pletely finished, which may have been one of the reasons why it was covered. An
                                                                                         organic layer, probably a lacquer, found between the background and the overpainting,
                                                                                         allowed the two layers to remain separate. This information along with the solubility
                                                                                         tests, supported the decision to remove the layer of black overpainting that bears no
                                                                                         relation to the original conception of the painting. The recovered landscape conforms
                                                                                         to the chromatic range and shapes of Leonardo’s ethereal landscapes, apart from
                                                                                         the obvious differences in the pictorial quality: for example, the rock in the area of the
                                                                                         mountains, located to the right of the figure, is the same as that in the autograph draw-
                                                                                         ing by Leonardo, in the Royal Collection at Windsor (c. 1510-15).
                                                                                             As for support, the work was carried out on a walnut panel, a support customarily
                                                                                         used by Leonardo and his circle in Milan, as can be seen in “Lady with an Ermine”, “La
                                                                                         Belle Ferronière” and “San Giovanni Battista” [9-10].
                                                                                             The preparation of the panel does not have the traditional plaster substrate. Instead,
                                                                                         it has a double preparation (a more orangey inner layer and a whiter outer layer) con-


                                                                                    62
sisting mainly of lead white. Test results, published in Volume 32 of the National Gal-
lery Technical Bulletin, conducted on other works by Leonardo, such as “Lady with an
Ermine” and “La Belle Ferronière”, show that although unusual, this type of preparation
was used in Leonardo’s workshop when the support was walnut [3, 9-10].
    Finally, the blue pigment obtained using costly lapis lazuli, imported from the coun-
try now called Afghanistan, seems to suggest that the copy was intended for a precise
destination and owner; it can therefore be assumed that it was not just a “workshop
experiment”. All in all, the materials used in the Prado panel are of high quality and the
work has been expertly executed [7].

   3.3. Comparative analysis

   The Prado copy is of great interest however, owing to the fact that the process used
to create the “Mona Lisa” can be retraced from the preparatory drawings to the final
layer, without any evident sign to indicate it was a copy.
   The comparative analysis using infrared revealed details identical to those under-
neath the paint layers, which show a parallel procedure. This document reports that the
figures are of the same size and shape and were probably transferred onto the respec-
tive supports using the same cartoon. The preparatory drawing of the original is not
so accurate as that of the copy (Figure 5) however, which has lines that indicate how
the position of the figure was moved; in addition, the intermediate phases of execution,
also found on the copy, are evident.




                                                                                                  CONSERVATION SCIENCE IN CULTURAL HERITAGE



Figure 5. Comparison between the Prado “Mona Lisa” and the Louvre “Mona Lisa”

   The brushstrokes that define the forms in the original painting also appear beneath
the pictorial surface of the Prado figure, though slightly displaced. They are found be-
neath the figure, on the waist, on the shoulders and hands, on the line of the breast, on
the folds of the sleeves and on the knees.
   Some of the contour lines of the initial figure in the Prado version were corrected
by hand and some fine lines drawn in black pencil and brush bearing no relationship
with the painted forms, are visible. However, they reflect the artist’s experiments and
hesitations, thus suggesting a much more complex creative process than that of a
normal copy.
   The most important point, however, is that each of the corrections to the underdraw-


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                                                                                         ing in the original, can also be found in the Prado version: the change in the contour of
                                                                                         the waistline which, as in the original, is covered by drapery on the surface, the position
                                                                                         of the fingers, the outline of the veil and head, including minor changes to the contours
                                                                                         of the cheeks and neck. A “traditional” copyist reproduces what can be seen on the
                                                                                         surface, but not what is hidden beneath. The existence of these changes beneath the
                                                                                         surface, common to both versions, reveals that the artist who painted the Prado copy
                                                                                         saw the entire procedure used for the “Mona Lisa” from conception to completion (Fig-
                                                                                         ure 6). In addition, he included elements that Leonardo drew on the underlayers, but
                                                                                         did not repeat on the surface, including the right armrest of the chair and some internal
                                                                                         parts of the robe [5].
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         Figure 6. Comparison between the Louvre “Mona Lisa” and the Prado “Mona Lisa”

                                                                                            3.4. Considerations

                                                                                            These reports have led to the identification of a ‘habitué’ of Leonardo’s workshop,
                                                                                         as the person who produced the Prado painting and that the copy and the original
                                                                                         were executed in parallel during the same time period. As for who the actual artist
                                                                                         was, the pictorial process is not comparable to the style of students or assistants such
                                                                                         as Boltraffio, Marco d’Oggiono and Ambrogio Predis, who all had well-defined artistic
                                                                                         personalities. Stylistically, however, the work can be placed in a Milanese context, ap-
                                                                                         proaching that of Salai or Francesco Melzi, perhaps Leonardo’s most trusted students,
                                                                                         the heirs of his work who had direct access to his landscape drawings.
                                                                                            The high quality of the materials used in the Prado painting suggests it is an impor-
                                                                                         tant commission. Diagnostic studies show that the Prado version was executed at the
                                                                                         same time as the original, supporting the hypothesis of a “duplicate”, produced at the
                                                                                         same time by someone who had direct access to the gradual procedure of creating
                                                                                         Leonardo’s original work [5,11].




                                                                                    64
   4. The Reynolds “Mona Lisa”

   4.1 Historical anamnesis

    In 1790, Sir Joshua Reynolds presented the 5th Duke of Leeds (a friend and member
of the Society of Dilettanti), with a self-portrait, now in the Royal Collection. The self-
portrait was a gift from Reynolds to the Duke, as a token of his gratitude for the copy
of the “Mona Lisa”, an oil on wood (Figure 7), he had earlier received from the Duke.




Figure 7. The Reynolds “Mona Lisa”

   Although certainly not by Leonardo, the painting is of considerable interest. It
is a well-made copy that in some ways has elements, such as the colour, that are




                                                                                                   CONSERVATION SCIENCE IN CULTURAL HERITAGE
not easily visible in the actual painting in the Louvre. Furthermore, the fact of hav-
ing been in the Reynolds collection, gives it considerable historical relevance.
The painting was probably copied by a French artist in the early seventeenth century,
from the original in Fontainebleau, or from a very accurate copy. From the point of view
of quality, this seems to be the copy that most closely matches the original.
   Reynolds was keenly interested in Leonardo, having studied him from an early age.
In Italy from 1750-1752 for the Grand Tour, he spent most of the time in Rome. Here,
he studied the old masters, ancient and modern art, assiduously. In the notebooks he
kept during this period, Reynolds refers only three times to Leonardo, while Michelan-
gelo and Raphael are cited numerous times. However, only a few works attributed to
Leonardo were available for viewing and none were in Rome.
   In one of his notebooks, Reynolds made an accurate drawing of a Madonna breast-
feeding the infant Jesus, writing “Leonardo da Vinci / Barberini”. This painting, housed
in Palazzo Barberini, is actually a copy, or a version of the “Virgin of the green cushion”
by Andrea Solario, a masterpiece influenced by Leonardo’s work, painted between
1507-1510, and now in the Louvre.
   Leonardo’s technique of overlapping colors to intensify areas of light with thin lay-
ers of light coloured pigment, or vice versa, to darken areas of shadow with layers of
light brown, is repeatedly emphasized by Reynolds: this interest in the Tuscan artist
most certainly had an influence on the art and techniques used by Reynolds for his
paintings.


                                                                                              65
                                                                                            As for the origin of the Reynolds copy, a late owner of the painting, Sir Abraham
                                                                                         Hume, states in the catalog of his collection (1829) that the painting had ‘very probably’
                                                                                         been owned by Jonathan Richardson (1665-1745), the English portrait painter and col-
                                                                                         lector of drawings by old Masters. Richardson’s essay on the theory of painting (1715)
                                                                                         must have influenced the young Reynolds in his successive speeches, so much so
                                                                                         that Reynolds bought many of his drawings.
                                                                                            As mentioned earlier, the painting was given to Reynolds by Francis Osborne, the
                                                                                         5th Duke of Leeds (1751-1799), who served as Foreign Secretary under William Pitt.
                                                                                         Reynolds says in his catalog that he asked the French secretary of the Académie
                                                                                         Royale, through ‘Monsieur Barbier’, if the “Mona Lisa” was still present in the King’s
                                                                                         study; the answer was that the work was still there, but not considered to be an original
                                                                                         and so of little prestige. The response must have encouraged Reynolds in his opinion
                                                                                         that the painting in his possession was actually the original.
                                                                                            Sir Abraham Hume (1749-1838), a famous collector of old masters, bought the
                                                                                         painting when Reynolds’ ancient masterpieces went up for sale in 1795. In his catalog,
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         Hume refers to Reynolds’ opinion that the painting was an original in spite of the paint-
                                                                                         ing in Paris, which he considered to be a fake.
                                                                                            When Waagen saw the Reynolds “Mona Lisa” in Hume’s collection, he described it
                                                                                         as ‘a new, very delicate and beautiful copy’. Hume bequeathed most of his collection,
                                                                                         including the “Mona Lisa”, to his nephew, John Hume Cust, Viscount Alford (1812 -51),
                                                                                         son of the first Earl of Brownlow. After Hume’s death, in 1838, his grandson moved
                                                                                         the collection to Ashridge Park, Hertfordshire. The painting was exhibited at the British
                                                                                         Institution in 1823 and at the Royal Academy Winter Exhibition in 1902 [6].

                                                                                           4.2 Analytical-diagnostic investigations

                                                                                            Analytical and diagnostic investigations have shed new light on the history of the
                                                                                         copy and how it was produced. The Courtauld report relating to the above investiga-
                                                                                         tions which came out in 2005, found that the artist must have been highly qualified,
                                                                                         as demonstrated by the refined preparatory drawing, his use of pigments, including
                                                                                         the sophisticated use of azurite for the sky and mountains, and also by the excellent
                                                                                         condition of the paint film. The materials and techniques are consistent with traditions
                                                                                         in northern Europe from the end of the sixteenth century until the early seventeenth
                                                                                         century.
                                                                                            It should also be noted that the right edge of the three horizontal panels, on which
                                                                                         the work was painted, was cut after the imprimatura was applied. The panel was prob-
                                                                                         ably originally designed for a larger painting, possibly a landscape. Ian Tyers used a
                                                                                         dendrochronological dating method for the support and concluded that the three pan-
                                                                                         els came from two oak trees of eastern Baltic origin, felled around 1602 and probably
                                                                                         originally used before 1634 [5].

                                                                                           4.3 Comparative analysis

                                                                                            The comparative analysis carried out by Matthew Landrus involved overlapping the
                                                                                         outlines of the copy with those of the Louvre painting. The comparison shows that the
                                                                                         majority of the contours and proportions in this work coincide with that in Paris. This
                                                                                         suggests that the painting may have been copied from the original, or from an exact
                                                                                         copy, through a mechanical process: it was probably traced with great accuracy on the


                                                                                    66
original painting. This thesis is supported by the fact that there is no trace of a quadra-
tura on the drawing beneath the painting. There are proportional coincidences in the
composition of the sections, both in the upper (head and landscape) and the lower
sections (hands and sleeves), suggesting that the copying process was done section
by section. Some outlines are not precisely accurate and do not perfectly match the
original forms, they are, nevertheless, almost identical, and the differences can be at-
tributed to unintentional slips during the tracing operation.

   4.4 Considerations

    Among the copies of a high standard listed by Frank Zollner and André Chastel, the
Reynolds seems to be the best, even if the face of the painted figure lacks the softness
and radiance of the original. The cheeks appear a little too wide and the chin too short,
but the face is delicately painted with a composed expression. The hands too, are well
painted. The technique of using opaque layers of paint, however, is very different from
the original.
    The dress is of a color closer to black than dark green and the garment’s folds must
have been painted when the original was already difficult to read. The sleeves seem to
have a reddish-brown enamel glaze tending to yellow, while the original, from descrip-
tions, must have been yellow, but now appears as a dull gold [9, 12].
    The landscape and the mountains, even if summarily painted, are more accurate
than those of other copies and have more details. The modelling of the parapet and
its linear decoration appear accurate. The chair armrest is difficult to see, but in the
underdrawing appears to be accurate. The base of the column to the right of the female
figure appears to be very precise.
    An interesting detail copied from the original that does not appear in other copies, is
the shadow projected forward from the base (unclear in the original).
    The Reynolds copy, like many others, enlarges every detail. Martin Kemp suggests




                                                                                                   CONSERVATION SCIENCE IN CULTURAL HERITAGE
that copyists were unnerved by the ‘daring’ way Leonardo had just hinted at the col-
umns, and so increased their size to create a more conventional setting.
    It is Reynolds and Hume who make the claim that their copy is better than the origi-
nal because it has colors and details that are not easily visible in its present condition,
as if obscured by discolored paint [6].
    The Reynolds “Mona Lisa” was probably painted by a French court artist in Fon-
tainebleau or a visiting artist at the beginning of the 17th century.
    The copy is slightly wider than the original with columns flanking the figure, whereas
in the Louvre “Mona Lisa” the columns are only suggested. The woman, in reality, is
sitting in a room in front of a window, in the style of Renaissance portraits.
    On the cleavage of the figure is a decoration which is part of the smock worn under
the gamurra (typical female dress of that period). Similar frills appear in four copies:
in one of Leonardo’s treatises on painting in 1651; in a print by Jean Masard of 1806,
which came out after the drawing of Bouillon; in the first French edition of the complete
paintings of Leonardo; in the engraving by Calamatta.
    There is no lace trimming on the original. There are darker areas above the breast
line, that could be the remains of some lace trimming rather than a shadow from the
top of the dress. Kemp has stated that this kind of detail is the last to be painted and
the first to be lost in any restoration.
    The Reynolds “Mona Lisa”, is currently on exhibition in the Dulwich Picture Gallery.


                                                                                              67
                                                                                         The Gallery director has said that the original in the Louvre has lost much of its original
                                                                                         color, the tones having become very dark. This worsening condition may be due to the
                                                                                         technique used in this situation by the Master, which was to create overlapping layers
                                                                                         of infinitely thin color, a process that had gone on for years. The change in the original
                                                                                         tone of color, also because of the age of the painting, has made it hard to read.
                                                                                             Instead, more traditional techniques have been used on the Reynolds “Mona Lisa”,
                                                                                         and the painted surface has” suffered “much less. It still has a surprisingly bright back-
                                                                                         ground and in this case too, as in the original, a pigment obtained with lapis lazuli
                                                                                         (extremely expensive) has been used to create the intense blue of the sky [6, 12,13].


                                                                                            5. The Isleworth “Mona Lisa”

                                                                                            5.1 Historical anamnesis
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                             In 1550 and also in 1568, Vasari declared in one of his writings that Leonardo had
                                                                                         left the painting of the “lady on the balcony” unfinished. The version in the Louvre, how-
                                                                                         ever, had already been completed by 1517, when it was shown by Leonardo himself to
                                                                                         the Cardinal of Aragon in Cloux. In this regard, the critical confrontation between the oil
                                                                                         painting on canvas, the Isleworth “Mona Lisa” (Figure 8), and the Louvre “Mona Lisa”,
                                                                                         proves to be of great importance in determining, as some scholars sustain, that the
                                                                                         Isleworth “Mona Lisa” may be an original by Leonardo.




                                                                                         Figure 8. The Isleworth “Mona Lisa”




                                                                                    68
   Further proof of the possible existence of another version of the portrait is repre-
sented by a pen and ink drawing, depicting a young woman on a balcony with columns,
by Raphael, dated around 1504 and probably executed when he was in Florence to
observe Leonardo’s work (Figure 9) [14]. When working, many students also took into
consideration this drawing, as well as taking inspiration from the study of Leonardo’s
portrait of the “Mona Lisa”. According to some historians, it was actually the Isleworth
“Mona Lisa” and its composition, that influenced Raphael’s style. Since the composi-
tional elements in it are unique and do not appear in any other painting, this “Mona
Lisa” must have been nearing completion when Raphael saw it in 1504.




                                                                                                  CONSERVATION SCIENCE IN CULTURAL HERITAGE
Figure 9. Raphael, “Head and shoulders of a woman”, Paris, Louvre, inv.3882 (pen and brown
ink, 22.2cm x 15.9cm)

   Several scholars have therefore hypothesized that the two versions of the “Mona
Lisa” have generated copies. The Louvre “Mona Lisa” has been the basis for numer-
ous copies throughout the centuries. In contrast, each copy in which the columns ap-
pear may have been inspired by the Isleworth version: for example, the Oslo “Mona
Lisa” (Figure 10) seems to be a direct copy of the Isleworth, as is also the “Mona Lisa
with Columns” in a private collection in St. Petersburg, Russia (Figure 1).
   When comparing the Isleworth “Mona Lisa” with all other paintings of the same
subject, additional impressive features are found that can only be attributed to the
hand of a great master. Among them are the details in the rendering and design of
the embroidery on the dress, which suggest a brilliant mind [5]. Furthermore, results
from the innovative method of computerised regression analysis, which incorporates
forensic techniques, have confirmed that the portraits are of the same woman at dif-
ferent ages, the difference between the one and the other being approximately 11
years [5].



                                                                                             69
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         Figure 10. The Oslo “Mona Lisa”

                                                                                            5.2 Analytical-diagnostic investigations

                                                                                             The beginning of the sixteenth century marked a period of transition that was ex-
                                                                                         tremely significant for artists’ materials. Venetian and Flemish masters’ knowledge
                                                                                         of the new media became widespread. Artificial oil paints and pigments began to be
                                                                                         popular. In fact Leonardo had used oil as a binder since his apprenticeship under Ver-
                                                                                         rocchio. Until then, wood had been the most important support for painting and before
                                                                                         1470 important works were almost never painted on canvas in Western art. Both “Lady
                                                                                         with an ermine” and “La Belle Ferronnière” were painted on walnut panels from the
                                                                                         same block of wood. On the contrary, the “Mona Lisa” in the Louvre is painted on pop-
                                                                                         lar wood, a wood most often used in Lombardy and Tuscany.
                                                                                             It should be remembered that Leonardo was not only a great inventor and innovator,
                                                                                         but also someone who assiduously experimented with new ideas and technologies.
                                                                                         Canvas was already being used in 1500 by many Italian artists. It is worth noting that
                                                                                         a small work of art, executed on parchment in 1490, has recently been authenticated
                                                                                         as the work of Leonardo. This is particularly noteworthy, given that until now no known
                                                                                         finished works of Leonardo are on this material. In his book “The Beautiful Princess”,
                                                                                         Martin Kemp writes: “He uses a medium that has not been previously observed in his
                                                                                         work, but that is closely connected with his interest in the French artist Jean Perreal. It
                                                                                         bears witness to his spectacular exploration and development of new media, tackling
                                                                                         each commission as a new technical and aesthetic challenge... “[5].


                                                                                    70
    In his “Treatise on Painting”, Leonardo describes in detail not only how to prepare
the canvas for painting, but also how to paint on it (“The mode of painting on canvas..”)
[5, 8, 12].
    Leonardo probably developed the technique of working on canvas during his ap-
prenticeship in the workshop of Verrocchio. One of the first references to the work of
Leonardo on canvas is by Giorgio Vasari, according to whom the master often used
linen or Rensa canvas, which was suitably prepared, to use in his studies. The Isle-
worth “Mona Lisa” consists of a hand-made linen cloth, a material with which Leonardo
had had significant experience before 1500, and is actually similar to the material used
for his studies on drapery.
    The main features of the linen cloth used for the Isleworth portrait of the “Mona Lisa”
are simple “tabby” weaves with an average count of 18 threads per cm2 in the warp and
16 threads per cm2 in the weft, that cross one another regularly, with some variation in
thickness. The result is a deformation in which the warp is slightly tighter than the weft.
It is no coincidence that Leonardo’s studies on drapery (now in the Louvre), dating
back to 30 years before had almost identical features. Just like the cloth of the “Mona
Lisa”, the cloth in his studies was hand woven.
    In 2005, the painting of a “Young Christ”, oil on thin cloth, probably linen, was pre-
sented by Alessandro Vezzosi as an unpublished work by Salai. In 1504, Salai was
introduced to Isabella d’Este as a talented and worthy pupil of Leonardo. It was also
at this time that canvas was used in Leonardo’s studio, and during this period that the
Isleworth “Mona Lisa” was painted. In 2011, Vezzosi presented other paintings with a
canvas support from the same period by Salai. This lends further credence to the idea
that this material was used in Leonardo’s studio in the late fifteenth century.
    It is evident that from the time of Leonardo’s work on, the use of canvas as a sup-
port became more common not only among Flemish and Venetian masters, but also
among German, Dutch, Florentine and other Italian masters [5].
    A more particular detail is the presence of a lining: it was commonly used on very old




                                                                                                   CONSERVATION SCIENCE IN CULTURAL HERITAGE
canvases to reinforce the original support by connecting it to a second new canvas or
‘lining’. The lining not only strengthened the original support, but helped in the overall
preservation of the picture. In the case of the Isleworth “Mona Lisa” it was made to
adhere by means of a mixture of glues: a combination of Venetian turpentine, flour
paste and gum as a plasticizer. The original canvas was cut slightly when the lining
was applied, but the rough edges with the original paint have not been touched. The
lining consists of a uniform fabric, obtained industrially, using a flat tabby weave, with
an average number of 14 threads per cm2 in the warp and 14 threads per cm2 in the
weft. The canvas is attached to a wooden frame, known as the stretcher, with nails.
Since there are no holes from nails in the previous lining, it can be assumed that the
current stretcher was inserted when the painting was lined [3, 5, 8, 15].
    The base ground layer is of a red-brown colour, a combination of red-brown ochre
calcite and some grains of quartz. Using this as a base color, the artist was able to
create a sense of warmth throughout the whole of the painting. The pigments are
mainly earths. The obvious lack of strong colors contributes to the intrinsic beauty of
the picture: all the chromatic elements are in organic harmony and contribute to ac-
centuating the beautiful skin tones. Part of this effect is in fact due to the undercoat of
reddish-brown.
    It is not the only painting where Leonardo used this technique. For example, it can
be seen in “Lady with an Ermine”, which underwent diagnostic tests at the National


                                                                                              71
                                                                                         Museum in Warsaw between 1952 and 1954. They revealed that the background of
                                                                                         the painting is a combination of bone black, earth of burnt umber and natural sienna.
                                                                                         The portrait was executed in Milan in 1490, it is therefore likely that pigments similar to
                                                                                         those used in Florence were available [22-23]. “La Belle Ferronnière” was examined
                                                                                         in the laboratories of the Louvre in the early fifties. In his book, “Leonardo da Vinci –
                                                                                         The Complete Paintings”, published in 2003, Pietro Marani reports on investigations
                                                                                         carried out by Sylvie Beguin, the renowned French curator, which revealed a thin paint
                                                                                         surface and an imprimatura of red earth already found in Leonardo’s work.
                                                                                             Marani later declared that the microscopic examination of the Louvre “Mona Lisa”
                                                                                         had revealed there were at least two colors in the preparatory layer: blue beneath the
                                                                                         upper section, in the landscape; red beneath the lower section. Leonardo had used the
                                                                                         same two-tone earth for, “La Belle Ferronière”, “The Musicians” and “Saint Anne” [16].
                                                                                             In 1974, the American conservator and scientist, H. Travers Newton, was in Florence
                                                                                         to attempt to find out about any remains of the “Battle of Anghiari” by Leonardo which
                                                                                         might be present under Vasari’s frescoes in Palazzo Vecchio. According to the writer,
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         Charles Nicholl, all the core samples showed a layer of red pigment under Vasari’s
                                                                                         plaster and a number of them showed other pigments, among which were those found
                                                                                         in the same red preparation. Two of them are typical of Leonardo’s painting technique: a
                                                                                         copper carbonate green, similar to that used for “The Last Supper”, for which Leonardo
                                                                                         provides a recipe in his “Treatise On Painting”, and smalt blue, found in the “Virgin of the
                                                                                         Rocks” in the Louvre. Furthermore, traces of azurite were found, an unsuitable pigment
                                                                                         for frescoes, which makes this particular fresco an unconventional work [8-9].
                                                                                             Based on these studies, it can be stated that in the painting “The Battle of Anghiari”
                                                                                         (c.1503), the use of a red ground is predominant, as is true of the Isleworth “Mona Lisa”
                                                                                         of the same period, and has the same red base. The dates of the two commissions
                                                                                         are also the same, so it is conceivable that the palette was the same. The background
                                                                                         landscape in the Isleworth “Mona Lisa”, also has traces of enamels and azurite, as
                                                                                         mentioned above in the results by H. Travers Newton.
                                                                                             A recent analysis of the pigments in the famous “Last Supper” by Leonardo has
                                                                                         drawn significant attention. During restoration of the painting, Antoinette Galone from
                                                                                         the Politecnico di Milano, revealed the presence of traces of calcite (calcium carbon-
                                                                                         ate) in the preparatory layers. It also identified a number of pigments that demonstrate
                                                                                         the work can be attributed to the Renaissance period.
                                                                                             In 1998, at the Congress of the ‘‘ International Institute for Conservation of Historic
                                                                                         and Artistic Works “in Dublin, Jill Dunkerton and Marika Spring of the National Gallery
                                                                                         in London, presented additional information:”With reference to the tinted and coloured
                                                                                         preparations, the thin pigmented layers found immediately above the plaster may be
                                                                                         part of some monochromatic underdrawings …”.
                                                                                             The first layer of gray, found in many Italian paintings of this period, corresponds to
                                                                                         materials found in samples from the Isleworth “Mona Lisa”.
                                                                                             It can therefore be said that the reddish brown ground in the Isleworth “Mona Lisa”
                                                                                         is compatible with other famous paintings by Leonardo, providing evidence of his crea-
                                                                                         tive ability and detailed knowledge of pigments. This talent enabled him to overcome
                                                                                         the challenge of reproducing natural colours, in other words, the way colours should be
                                                                                         perceived by the human eye in real life. The reddish-brown ground can also be seen in
                                                                                         many of his drawings and studies, some of which are in the Royal Library in Windsor
                                                                                         and the Uffizi Gallery Museum in Florence.
                                                                                             The successive layer, which is grey with a slight purplish hue, is made from calcium


                                                                                    72
carbonate, lead white and bone black. The same colours and techniques are again
mentioned by Leonardo in his Treatise.
    In the 1996 National Gallery Technical Bulletin (Vol. 17), in the article “Giampietrino,
Boltraffio, and the influence of Leonardo”, L.Keith and A.Roy wrote: “In Leonardo’s
paintings, the overall pictorial unity, produced using a tightly controlled, restricted
range of tones, was a central feature. The sculptural plasticity of the London National
Gallery’s cartoon of the “Virgin and Child with Saint Anne” and “St. John the Baptist”,
together with the use of a restricted palette, illustrate Leonardo’s primary concern with
the creation of depth through the manipulation of the sfumato and not of colour. In his
painting, while developing techniques to exploit colour by decreasing its intensity so as
to create aerial perspective, the intrinsic beauty of certain naturally high-key pigments
was, as a rule, deliberately and consistently subordinated to the constraints dictated by
his great discipline in the use of sfumato” [5].
    In order to identify the complete range of pigments and other media used, as well as
determining some of the techniques used in preparing the support, two campaigns of
analytical investigations were performed on the painting: the first in 1977, by Hermann
Kuhn, under the supervision of the Swiss Institute for Art Research; the second, in 2005
by Maurizio Seracini. The results are not only consistent with each other, but are compat-
ible with the palette used in the version of the Louvre. Reflectographic investigations per-
formed in January 2011 by Pascal Cotte, show that the painting has some clear prepara-
tory drawings below the painting surface. This therefore means that it is not a direct copy.
    Leonardo’s interest in geometry is well-known and well-documented. In this regard,
the Isleworth “Mona Lisa” is perfectly in line with the “golden ratio”. The painting has
also been subjected to two different sets of dating analyses: radiometric (210Pb) and
radiocarbon [5].
    210
        Pb dating was carried out on a sample of white lead in order to determine whether
the work was executed pre- or post- 1750: the chemical composition after this date
changes. The materials present in the examined sample indicate a date prior to 1750,




                                                                                                    CONSERVATION SCIENCE IN CULTURAL HERITAGE
a date that includes the early sixteenth century.
    Radiocarbon dating conducted on the canvas indicates, with a probability of 95.4%,
a date no later than the 1500s. This is in line with the hypothesis of the painting being
executed at the beginning of the sixteenth century.

   5.3 Comparative analysis

    When comparing the two versions of the “Mona Lisa” by Leonardo, some significant
differences immediately come to notice, which suggest that Leonardo’s intention from
the very beginning was to paint two separate portraits [5].
    Firstly, the different dimensions: the Isleworth version is 64.5 cm wide and 86 cm
high; the Louvre version has a slightly irregular width of 53.3 cm at the top, and 53.4
cm at the bottom, with a height of 79.2 cm on the right, 79.1 cm on the left and 79.4
cm in the middle. As for the support, the Isleworth painting is on canvas, the Louvre
version is on poplar wood.
    Though representing the same woman, their ages are different: in the Isleworth ver-
sion the woman is 22 or 23; in the Louvre version the subject is 11 or 12 years older.
    As for the composition, the young Mona Lisa in the Isleworth version is sitting in an
open loggia framed by two columns, one on either side.
    The woman is sitting turned to face the viewer more directly. Her head and right


                                                                                               73
                                                                                         shoulder are tilted slightly forward. Her neck muscles are tense, allowing the artist to
                                                                                         emphasize this angle with superb effects of light on the neck.
                                                                                             Despite the smaller size, in the Louvre version the mass of the figure leans further
                                                                                         forward. The female figure occupies more space, the geometry being further accentu-
                                                                                         ated by the effect of the glaze, a technique perfected by Leonardo after 1508. There
                                                                                         are slight traces of the pillars at the edge of the picture, but it is possible they were not
                                                                                         part of the original composition. They may have been added by a restorer who had
                                                                                         taken into consideration the Isleworth version. The woman is sitting more upright, mak-
                                                                                         ing the neck appear more relaxed.
                                                                                             One of the predominant features of Leonardo’s portraits is the contrast between the
                                                                                         warmer tones of the hands and pale complexion of the face and chest.
                                                                                             In the Isleworth version the hands are thinner, the fingers more slender and the
                                                                                         index finger of the right hand is more relaxed than in the Louvre version.
                                                                                             The background in the Isleworth “Mona Lisa” is markedly different. It has remained
                                                                                         largely unfinished (as is the area of the sky). This topic is discussed in several original
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         texts and is also mentioned by Vasari. Reference is made to an unfinished “Mona Lisa”
                                                                                         and no mention is made of any type of landscape. Originally, the group of trees on the
                                                                                         left side was reflected in a small blue lake. A trace of blue is visible beneath the paint,
                                                                                         indicating that the area was completely repainted during a restoration carried out by
                                                                                         someone whose talent by no means matched that of the original master.
                                                                                             Leonardo’s imaginary landscapes in the Louvre “Mona Lisa” remain a mysterious
                                                                                         enigma. The landscape below is certainly more comprehensible and, in this regard,
                                                                                         some scholars have come to identify the place through recognition of the famous
                                                                                         bridge behind the figure. The landscape higher up is pure fantasy. Carlo Pedretti wrote
                                                                                         that: “The landscape in the painting in the Louvre, is more in line with Leonardo’s sci-
                                                                                         entific views in 1508 or later versions.”
                                                                                             This comment further explains the dating of the painting, which can be considered
                                                                                         as one of Leonardo’s last works. It is interesting to note that Leonardo uses the device
                                                                                         of the background with numerous rocky masses on many occasions and can be found
                                                                                         in the “Annunciation” of 1472-1475 and the “Madonna of the Carnation” of 1478-1480.

                                                                                            5.4. Considerations

                                                                                             Results from previous analyses indicate that all the pigments found were already
                                                                                         available and in use at the beginning of the sixteenth century.
                                                                                             A comparison between the pigments used in the two paintings of the “Mona Lisa”,
                                                                                         leads to interesting results. The white lead, for example, is an important component in
                                                                                         both works. As regards the young “Mona Lisa”, both Kuhn and Seracini have detected
                                                                                         the presence of lead white in each single analysis, including the grey ground (5). The
                                                                                         Louvre report on the state of the “Mona Lisa” confirms that lead is present in the form
                                                                                         of white lead throughout the painting [4].
                                                                                             Other pigments common to both works are azurite, copper blue, vermilion and um-
                                                                                         ber. In fact, both paintings have a substantial amount of earth pigments, such as the
                                                                                         different range of siennas, ochres and umbers, which was quite common for this pe-
                                                                                         riod, when artificial pigments were not yet available. There are, in addition, many vari-
                                                                                         ations of black.
                                                                                             Burnt umber is an earth tone used in both paintings, with wonderful mineral proper-
                                                                                         ties. This suggests that the burnt umber, or at least a pigment rich in manganese oxide,


                                                                                    74
plays an important role in achieving the famous sfumato effect typical of Leonardo. The
relative absence of craquelure in the shadows of the face may be related to the drying
properties of this pigment, which originally comes from Umbria, a region famous for
the quality of its pottery.
   Traces of smalt were found exclusively in the landscape background of the younger
version of the “Mona Lisa”. The popularity of the pigments used by the artist became
widespread only in the second half of the sixteenth century. However, according to
scientists from the Centre for Research and Restoration of the Museums of France,
the use of smalt in easel painting was already well known, albeit to a lesser extent, in
the second half of the fifteenth century [12].
   One problem that many artists of that time faced, was the lack of availability of the pig-
ments they needed. Creating the right colours and tones from minerals and earths, using
suitable binders to obtain the appropriate texture, was a laborious process and therefore
costly. Many of these pigments were imported from the major art centers of Italy, the
Netherlands, France and England, but they were expensive and not always readily avail-
able. It is consequently understandable how eager artists were to learn the process of
creating artificial pigments that could serve as alternatives to the traditional palette.
   In Leonardo’s Treatise, there is a reference to “... a veil of colour diluted with dry
cinnabar”. This is present in the Isleworth “Mona Lisa”, in a sample of the flesh tones,
but is not mentioned in the Louvre “Mona Lisa”. In the latter painting, there is a small
amount of vermilion in some of the flesh tones, as in the younger version. Leonardo
mentions the red lake pigment as being the correct one for shadows and areas of light.
Again, both paintings show traces on the young woman’s face, and in the Louvre ver-
sion, on the hands [5].
   Finally, the Mona Lisa Foundation (the Foundation that has made a thorough study of
the work), as well as many experts, are oriented toward confirming the Isleworth painting
as genuine and executed in a period that is earlier than the version in the Louvre.




                                                                                                     CONSERVATION SCIENCE IN CULTURAL HERITAGE
   6. Comparisons between the columns and the embroidery of the dress in the
   different copies

    At this stage of the research, it was decided to investigate certain aspects in more
detail by comparing four versions of the “Mona Lisa”: the Isleworth, the Oslo, the Lou-
vre and the Prado. The investigated features relate to the presence of the columns,
and the decorations embroidered on the dress found in a number of the paintings.
    When looking at the Louvre version, the female figure naturally stands out from the
background. This has led to the supposition that the wood panel, at one time, must
have been wider, thus allowing for the insertion of the columns or other device, so as
to frame the figure in a more particular composition, as the base of the columns and
barely visible vertical lines would seem to indicate.
    In 1959, the distinguished German art historian Richard Friedenthal stated that “...
[ the “Mona Lisa “in the Louvre] was cut by about 10 cm on each side.” This would
confirm that the panel was larger by about 20 centimeters [13].
    When Pedretti also declared that the architecture of the Louvre version of the “Mona
Lisa” would have been better with columns framing the composition, he noted that: “The
lady sits by the parapet of a loggia, which was originally extended at each side to include
two columns framing the landscape, as in a window. These are now reduced to little more


                                                                                                75
                                                                                         than vertical strips, but their bases are easily visible and their foreshortening offers the
                                                                                         only element of linear perspective in the picture. Originally therefore, the overwhelming
                                                                                         presence of the lady was kept in check by the architectural structure of her setting “[14].
                                                                                             Serge Bramly writes: “The panel has lost a strip of about seven centimeters from
                                                                                         each side: we can no longer see the two columns that originally framed the landscape,
                                                                                         which appear in old copies and in Raphael’s drawing [15].
                                                                                             In a later book Bramly says: “Like so many of Leonardo’s works, the “Mona Lisa”
                                                                                         has suffered both from the ravages of time and from rough treatment by restorers: it
                                                                                         has been narrowed by six or seven centimeters on both the right and left “[16].
                                                                                             On the other hand, in his letter to Murray Urquhart of 25 February 1943, the scholar
                                                                                         Kenneth Clark, opines that the columns were evidently intended to be part of the origi-
                                                                                         nal design, but were added later.
                                                                                             However, all this speculation ended, when, in October 2004, the Louvre version was
                                                                                         subjected to a series of diagnostic tests carried out by a group of 39 international ex-
                                                                                         perts. In the report concerning the edges of the poplar support, results showed that over
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         the centuries, the sides of the panel had actually been trimmed a little, but only on the
                                                                                         unpainted part: “Careful examination of the side edges in section reveals open burrow
                                                                                         holes caused by parasites, which indicate that the plank’s width was trimmed a second
                                                                                         time. This trimming clearly only involved the bare wood and not the painted layer” [2-17].
                                                                                             Additional documents of the Louvre on this matter, state: “The absence of any prep-
                                                                                         aration on the covered edges thus provides us with irrefutable testimony of the original
                                                                                         dimensions of the painting itself”. The report contains the following conclusions:
                                                                                             •    it is clear that the “Mona Lisa” in the Louvre, originally had no columns [2];
                                                                                             •    it follows, therefore, that any version or copy of the “Mona Lisa” in which the
                                                                                                  columns are represented, must have originated from another painting, probably
                                                                                                  the younger version of the “Mona Lisa” (Isleworth). This painting may have in-
                                                                                                  spired the artist who later included the columns in the Louvre version [5];
                                                                                             •    many scholars currently believe that the matrix of the copies with columns, is
                                                                                                  the Isleworth “Mona Lisa”, the composition of which provides for a clear devel-
                                                                                                  opment of the columns in their entirety [5].
                                                                                             It does not however exclude a further hypothesis: there are comments in reference
                                                                                         to the barely visible vertical lines, and the bases of the columns visible in part in the
                                                                                         Louvre “Mona Lisa”. In general, Leonardo’s compositions followed strict mathematical
                                                                                         principles and certainly the Master’s ability in describing reality had already been ac-
                                                                                         quired by the beginning of the sixteenth century. Logically, if he had intended to frame
                                                                                         the Louvre “Mona Lisa” between two columns, he would certainly have painted them
                                                                                         in the correct manner, by giving them a special space in the geometry of the structure.
                                                                                         Leonardo himself points out that: “No human investigation can be a real science unless
                                                                                         it can be demonstrated mathematically.”
                                                                                             Hence, there is a strong feeling that, at some point in the painting’s history, a re-
                                                                                         storer considered that the portrait would look better with columns, despite the fact they
                                                                                         would not be really evident [5]. This assumption, however, has not yet been scientifi-
                                                                                         cally proven.
                                                                                             Likewise, there are several significant differences in the embroidery on the dress, in
                                                                                         the various copies and the original. For this reason, a comparison will be made of the
                                                                                         Isleworth “Mona Lisa” (the earlier “Mona Lisa”), the Oslo copy, the Louvre “Mona Lisa”,
                                                                                         and the Prado copy, with regard to the portion representing the columns (Figs. 11-13)
                                                                                         and the embroidered dress (Figs. 14-17).


                                                                                    76
Figure 11. Comparison of the columns

   As regards the left-hand column, in more detail (Figure 12):
   L1. Isleworth version: in this work, the column and its base are clearly part of the
original composition and not an afterthought. In addition, in accordance with Leon-
ardo’s studies on light, the shadow of the columns falls softly on the balcony ledge.
   L2. Oslo copy: in this work, the details and composition of the Isleworth version
have been copied: in particular, the column, the base, the shadow on the ledge and
most of the landscape through the trees.
   L3. Louvre version: the column, barely visible, and its base, seem to have been
added later, by another artist. The base has been painted inaccurately and there is no




                                                                                               CONSERVATION SCIENCE IN CULTURAL HERITAGE
shadow on the balcony ledge.
   L4. Prado copy: the base of the column is more shapely than the one in the version
of the Louvre, which they have tried to reproduce, and once more, the shadow on the
balcony ledge is missing [5.7].




Figure 12. Comparison of the left column


                                                                                          77
                                                                                             As regards the right-hand column (Figure 13):
                                                                                             R1. Isleworth version: among the different versions and copies of the “Mona Lisa”,
                                                                                         the right-hand column and base demonstrate confidence in the design and knowledge
                                                                                         of classical architecture. This painting is believed to be the true genesis in relation to
                                                                                         the composition of the flanking columns and may also have been a model for some of
                                                                                         Raphael’s early works from the sixteenth century.
                                                                                             R2. Oslo copy: as with the left side of the painting, the copyist accurately repro-
                                                                                         duces the composition with the columns on each side, as well as Leonardo’s Florentine
                                                                                         landscape from the Isleworth version.
                                                                                             R3. Louvre version: on the right side too, the column is barely visible, and the base
                                                                                         is evidence that it was painted on the landscape and was therefore probably not part
                                                                                         of the original composition.
                                                                                             R4. Prado copy: in this case too, there is a great deal of evidence (including the
                                                                                         bridge) that proves it is based on the Louvre version. However, the details on the
                                                                                         base have a different shape to those on the left and the perspective is imprecise
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         [5,7].




                                                                                         Figure 13. Comparison of the right column

                                                                                           In comparing the embroidery of the dress in the different versions and copies of the
                                                                                         “Mona Lisa” (Figs. 14-17), it is to be noted that:
                                                                                           •    in the Isleworth version, the embroidery is done in a loose horizontal style (Fig-
                                                                                                ure 14);
                                                                                           •    in the Louvre version, the design of the embroidery has a closer oval vertical
                                                                                                pattern, further evidence of the diversity of the two paintings (Figure 15);
                                                                                           •    in the Oslo copy, the embroidery follows the same horizontal pattern of the
                                                                                                Isleworth version (Figure 16);
                                                                                           •    in the Prado copy, unlike in the others, the pattern in the embroidery is more
                                                                                                rounded (Figure 17) [5-19].




                                                                                    78
Figure 14. Embroidery on the dress of the Isleworth “Mona Lisa”




Figure 15. Embroidery on the dress of the Louvre “Mona Lisa”




                                                                       CONSERVATION SCIENCE IN CULTURAL HERITAGE

Figure 16. Embroidery on the dress of the Oslo “Mona Lisa”




Figure 17. Embroidery on the dress of the Prado “Mona Lisa”



                                                                  79
                                                                                             Some further considerations can be made regarding certain details of the embroi-
                                                                                         dery relating to the repetition of the “cloverleaf” pattern, the regularity in the design, the
                                                                                         irregularities in the interwoven “cloverleaf” and the gala (trimming).
                                                                                             As regards the recurrence of the ‘cloverleaf’, the following differences have been noted.
                                                                                         The Isleworth version shows continuity in the repetition of the “cloverleaf” twice on the
                                                                                         bodice.
                                                                                             In the Louvre version, Leonardo went ‘out of sequence’ in the centre by using three
                                                                                         rings among the cloverleaves. From this, it can be assumed that this painting is not
                                                                                         only different from the Isleworth “Mona Lisa”, but that – the bodice at least – was
                                                                                         probably painted at a later date. The three rings in the center are another indication of
                                                                                         Leonardo’s intention to differentiate the paintings. The “Mona Lisa” in the Louvre is the
                                                                                         only painting of this subject in which the detail of the three rings is found.
                                                                                             In the Oslo and Prado copies a repetitive pattern of two cycles can be seen between
                                                                                         each cloverleaf [5].
                                                                                             As regards the irregularities in the interweaving of the ‘cloverleaf’, in the Isleworth
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         version each individual group of cloverleaves has a unique pattern, identified by a
                                                                                         slight difference in the threading of the pattern, no two are the same. This feature itself
                                                                                         identifies the Isleworth version in a significant way, as being a unique original version.
                                                                                         In the Louvre version and the Oslo and Prado copies, the cloverleaves have a repeti-
                                                                                         tive pattern [5].
                                                                                             The gala, a delicate ruffle at the top of the bodice, is clearly visible only in the Prado
                                                                                         copy. In the other works examined, however, this detail is no longer visible [5].


                                                                                            7. Final considerations

                                                                                             Firstly, study of the paintings has highlighted not only the presence of two ver-
                                                                                         sions of the “Mona Lisa”, but also the necessary distinction between the copies and
                                                                                         aforementioned versions: for versions, read the Isleworth “Mona Lisa” and the Louvre
                                                                                         “Mona Lisa”. These are to be considered, therefore, two original works, as they were
                                                                                         both painted by Leonardo in two different periods. The subject is the same, but the
                                                                                         paintings vary considerably, making them two works in their own right and not a copy
                                                                                         of each other.
                                                                                             Consequently, it can be assumed that all subsequent copies of the “Mona Lisa” are
                                                                                         in fact copies of one version or the other, or a combination of both.
                                                                                             The workmanship of the “Mona Lisa” copies is heterogeneous: there are over sixty
                                                                                         recorded copies and probably others that have yet to be discovered. The works are
                                                                                         often of good quality and painted by talented artists, others are of inferior quality. This
                                                                                         is probably also due to the fact that shortly after the death of its author, the “Mona Lisa”
                                                                                         became a true “icon”. This also meant that it was studied and used as a means of test-
                                                                                         ing the skills of those who wanted to pursue a career in the arts and inevitably had to
                                                                                         look to the greatest master of the Italian Renaissance – an artist who had invented a
                                                                                         new way of doing and feeling art [18, 21].
                                                                                             Carlo Pedretti claims that none of the known copies reproduces the transparent
                                                                                         veils which follow the woman’s contours in the original (such as in the left arm up to
                                                                                         and past the elbow) [22]. Just as there is difficulty in reading the color of the dress and
                                                                                         the folds of the clothes on the figure, it is equally difficult to reproduce the infinitely
                                                                                         subtle gradations of the bright tones transposed in the modeling of the face and hands,


                                                                                    80
tones that Leonardo produced layer by layer, over many years, with small transparent
brushstrokes [21-27].
    Part of the “Mona Lisa’s” charm is in the difficulty of reproducing it. All copies and prints
have given rise to discussions regarding their date of execution and the sources used.
The way in which the figure is given substance and depth through the transparent
veils, the scarf and the folds of the clothes, escapes the copyists, just as the complexity
of the landscape does, with its aerial perspective, gradually receding into the distant
mountains that gently merge into the sky.
    The brushstrokes in the copies are generally not full-bodied, unlike the original, in
which the landscape is characterized by the typical thickness of the colors, often ob-
tained by spreading them with the fingertips.
    It is almost impossible to find the same depth, the luministic vibrations, the same
play of chiaroscuro, the suffused glow, typical of Leonardo’s masterpiece.
    Copyists were probably unnerved by the bold way in which the columns had simply
been suggested in the original, and so enlarged them to create a more conventional
frame [5].
    Nowadays, works that have been generally attributed to Leonardo, and exhibited
in major museums and galleries, are not always universally recognized as originals.
Experts’ opinions are likely to change, often on the basis of new evidence, further
reflection, studies, or simply a change of mind, but it is the thorough examination of a
painting which can often reveal important features that are not evident in the accompa-
nying documentation. Art-historical judgements are not a “definitive” science, but the
art world still relies heavily on the opinions of experts.
    The fame of the “Mona Lisa’” also derives from the cult of its author, Leonardo, and
the acclaim the painting has received from the time it was painted to the present day [6].
    All the above points highlight the distinctive artistic features of this universal art work.
It is for this fundamental motivation, but not the only one that, in continuing the histori-
cal, artistic and diagnostic-analytical study of the painting “Mona Lisa with columns”




                                                                                                         CONSERVATION SCIENCE IN CULTURAL HERITAGE
[1], it was considered appropriate to compare results with:
    •     investigations carried out on the “Mona Lisa” at the Louvre in 2004 by the “Cen-
          ter for Research and Restoration of the Museums of France,” collected in the
          compendium, “Au coeur de la Joconde-Leonard de Vinci décodé” [2];
    •     historical and technical study of other works by Leonardo, carried out by the
          National Gallery [3];
    •     historical and technical studies of several copies of the “Mona Lisa”, such as
          the Prado and Reynolds copies, as well as the version, known as the “younger
          Mona Lisa”, the Isleworth painting [5].
    As regards the study of other copies, it can be said that:
    •     the Prado copy was painted in Leonardo’s workshop in parallel with the original
          [7];
    •     the Reynolds “Mona Lisa” is one of the copies that provides the most clues
          about what the original has lost over time, but also succeeds in demonstrating
          the “magic” of Leonardo’s work. However, the Reynolds “Mona Lisa”, though
          well executed, is unable to recreate the infinitely subtle shades of light and
          shadow, especially in the modelling of the face and hands [6];
    •     the Mona Lisa Foundation as well as many experts are inclined towards con-
          firming the Isleworth “Mona Lisa” as authentic and probably executed before
          the version in the Louvre [5].


                                                                                                    81
                                                                                            To conclude, the following statement by Kemp, a leading Leonardo scholar and
                                                                                         curator of the exhibition of Leonardo’s drawings at the Victoria and Albert Museum in
                                                                                         London [6], sums up the exclusive and shared characteristics of Leonardo’s genius:
                                                                                            “There is something intangible and unique when you are in front of a work by Leon-
                                                                                         ardo, it cannot therefore be compared, much less, replicated”.


                                                                                               References

                                                                                         [1]     LORUSSO S, MATTEUCCI C, NATALI A, APICELLA S., FIORILLO F. 2013, Di-
                                                                                                 agnostic-analytical study of the painting “Gioconda with columns” Conservation
                                                                                                 Science in Cultural Heritage. vol. 13, pp. 75-127 ISSN: 1974-4951
                                                                                         [2]     MOHEN J.P. 2005, Au coeur de La Joconde. Léonard de Vinci décodé, (ed.)
                                                                                                 Center for Research and Restoration of the Museums of France, Musée du Lou-
                                                                                                 vre éditions.
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




                                                                                         [3]     LARRY K., ROY A., MORRISON R., SCHADE P. 2011, Leonardo da Vinci’s Vir-
                                                                                                 gin of the Rocks: Treatment and Display, National Gallery Technical Bulletin, n.32
                                                                                         [4]     Hommage à Léonard de Vinci: expositìon en l’honneur du cinquieme centenaire
                                                                                                 de sa naissance, Musée du Louvre 1952.
                                                                                         [5]     The Mona Lisa Foundation, www.monalisa.org
                                                                                         [6]     The International Art Magazine, www.apollo-magazine.com
                                                                                         [7]     https://www.pinterest.com
                                                                                         [8]     Ed. PIVA G. 2007, L’arte del restauro: il restauro dei dipinti nel sistema antico
                                                                                                 e moderno, secondo le opere di Secco-Suardo e del Prof. R. Mancia, Milano,
                                                                                                 Editore Ulrico Hoepli.
                                                                                         [9]     ZÖLLNER F. 2007, Leonardo da Vinci, tutti i dipinti e disegni, Modena, Taschen.
                                                                                         [10]    THE METROPOLITAN MUSEUM OF ART, 2003, Leonardo da Vinci master
                                                                                                 draftsman, New York, Metropolitan Museum of Art.
                                                                                         [11]    Leonardo da Vinci, Volume 1,(Ed) Istituto Geografico de Agostani, Novara.
                                                                                         [12]    RINALDI S., QUARTULLO G., et al, 1995, La fabbrica dei colori. Pigmenti e col-
                                                                                                 oranti nella pittura e nella tintoria, Roma, Bagatto libri.
                                                                                         [13]    FRIEDENTHAL R., 1959, Leonardo da Vinci; a pictorial biography, New York,
                                                                                                 Viking Press
                                                                                         [14]    PEDRETTI C, 1973, Leonardo – A study in chronology and style, London,
                                                                                                 Thames and Hudson
                                                                                         [15]    BRAMLY S., 1994, Leonardo: The Artist and the Man, Penguin,
                                                                                         [16]    BRAMLY S, 1998, Léonard de Vinci, éditions Lattès,
                                                                                         [17]    FIORI C., LORUSSO S., PENTRELLA L. 2003, Restauro, manutenzione, conser-
                                                                                                 vazione dei Beni Culturali: materiali, prodotti e tecniche, Bologna, Pitagora Edi-
                                                                                                 trice.
                                                                                         [18]    http://www.beniculturali.it/mibac/multimedia/MiBAC/minisiti/Liocorno/disegnol-
                                                                                                 ouvre
                                                                                         [19]    LORUSSO S., GALLOTTI L. 2007, Caratterizzazione, tecnologia e conservazi-
                                                                                                 one dei manufatti tessili, Bologna, Pitagora Editrice.
                                                                                         [20]    MARANI P. 2000, Leonardo da Vinci. The complete paintings, New York, Harry
                                                                                                 N. Abrams.
                                                                                         [21]    PAPA R. 2011, Leonardo. La tecnica pittorica, in Art e Dossier n. 281, Milano,
                                                                                                 Giunti.


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[22] PEDRETTI C. 2005, Leonardo. La pittura, in Art Dossier, n.215, Milano, Giunti.
[23] ROSENBERG P. 1999, La pittura in Europa: la pittura francese, Milano, Electa
     Mondadori.
[24] MARTIN G. 1970, Flemish school, 1600-1900, London, National Gallery Cata-
     logues.
[25] VILLERS C., 1981, Artists’ canvases, Proceedings of the ICOM committee for
     conservation, vol. 2, pp. 1-12. Ottawa
[26] MARANI P. C., 2000, Leonardo da Vinci. The complete paintings, Harry N.
     Abrams, New York
[27] LARRY K., ROY A., MORRISON R., SCHADE P., 2011, Leonardo da Vinci’s Vir-
     gin of the Rocks: Treatment, Technique and Display, National Gallery Technical
     Bulletin, n.32


   Biographical notes

     Salvatore Lorusso, former full Professor in “Chemistry of the Environment and
Cultural Heritage” in the Department of Cultural Heritage at the University of Bolo-
gna (Ravenna Campus), continues his academic activities in various fields. His sci-
entific activity continues as a member of the Scientific Committee of the project “Joint
Research Laboratory for Cultural Heritage Diagnosis and Conservation”, within the
Agreement of Cooperation between the University of Bologna, Italy, and Zhejiang Uni-
versity, China. He is the founder and Director of two book series: the first “I beni cultur-
ali e l’ambiente” consisting of 11 volumes (Pitagora Editrice, Bologna), and the second
“La formazione e la ricerca nel settore dei beni culturali e ambientali” of two volumes
(Mimesis Edizioni, Milano-Udine). He is also Editor-in-Chief of the historical-technical
Journal “Conservation Science in Cultural Heritage” (Mimesis Edizioni, Milano-Udine).
     He is the author of more than 400 publications in national and international scien-




                                                                                                    CONSERVATION SCIENCE IN CULTURAL HERITAGE
tific journals and congress proceedings, and of 22 volumes covering subjects such as
commodity science and the system: artifact-environment-biota. He is a Foreign Mem-
ber of the Russian Academy of Natural Sciences; the former Vice-president, he is now
a Councilor of the Presidency of the Società Italiana per il Progresso delle Scienze
(SIPS – founded in 1839); Director General of the Academy of Food and Wine Culture;
member of the Scientific Committee of the network “Gardens of Babylon – Green Hub”;
Emeritus Professor and Visiting Professor of the Cultural Heritage Institute of Zhejiang
University (China); President of the Academic Committee of National Cultural Heritage
Preservation (Cultural Relics Bureau of Zhejiang Province). His biography appears in
the 2016 Marquis Edition of “Who’s Who in the World”.

   Andrea Natali is Adjunct Professor and Research Fellow at the Department of Cul-
tural Heritage of the Alma Mater University of Bologna. He graduated in “Conserva-
tion of Cultural Heritage” in the University of Tuscia, Viterbo. He carries out scientific
and didactic activities in the field of conservation environment, employing diagnostic
techniques for evaluating the conservation state of cultural heritage, art diagnostics
and authentication of art works, including the management and valorization of cultural
heritage and landscape, and planning and promotion of artistic and cultural events. He
is a mediator/conciliator (Ministerial Decree n.180 18th October 2010). He is professor
on the Master (1st level) “Planning and Promotion of artistic and Cultural Events” at


                                                                                               83
                                                                                         the Alma Mater Studiorum University of Bologna. He is author and co-author of over
                                                                                         40 publications covering the preservation and valorization of cultural heritage, and
                                                                                         monographs and scientific treatises used as university text books. He is part of the
                                                                                         Scientific Committee and Coordination of the Journal “Scienze e Ricerche”, and the
                                                                                         Editorial Coordinator of the Journal “Conservation Science in Cultural Heritage”. He is
                                                                                         an honorary member of the Academy of Food and Wine Culture.
S. Lorusso, A. Natali - Mona Lisa: a comparative evaluation of the different versions




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