Iron gall ink  From Wikipedia, the free encyclopedia Jump to:
navigation, search Oak galls and iron(II) sulfate, ingredients
of iron gall ink  Iron gall ink (also known as iron gall nut ink
or oak gall ink) is a purple-black or brown-black ink made from
iron salts and tannic acids from vegetable sources. It was the
standard writing and drawing ink in Europe, from about the 5th
century to the 19th century, and remained in use well into the
20th century.  Preparation and use[edit]  Homemade ink. On left,
solution of iron (from nails) and vinegar. On right, oak
extraction. The two are mixed immediately prior to use to
produce the ink, center.  The ink was generally prepared by
adding some iron(II) sulfate (FeSO4) to a solution of tannic
acid (C6H2(OH)3COOH), but any iron ion donor (e.g. nails, iron
metal scraps, etc.) can be used. The gallotannic acid was
usually extracted from oak galls (also known as "oak apples"),
or galls of other trees; hence the name. Fermentation or
hydrolysis of the extract releases tann