Raku ware

From Wikipedia, the free encyclopedia
Jump to: navigation, search
White Raku teabowl Fuji-san (Mount Fuji) by Honami Kōetsu, Edo period, 17th century. National Treasure.



An Azuchi-Momoyama period (16th century) black Raku-style chawan, used for thick tea (Tokyo National Museum)
Black Raku teabowl Shōrei (Aged Pine) with crane design by Raku IX (Ryōnyū), c. 1810-1838






Oxidation reduction[edit]

Raku ware in the kiln, reaching white hot temperatures

In the western style of raku firing, the aluminium container acts as a reduction chamber, which is a container that allows the carbon dioxide to pass through a small hole.[2] A reduction atmosphere is created by closing the container.[2] A reduction atmosphere induces a reaction between oxygen and the clay minerals, which affects[vague] the color.[3] It also affects the metal elements of the glaze[vague]. Reduction is a decrease in oxidation number.[3] Closing the can reduces the oxygen content after the combustible materials such as sawdust catch fire and forces the reaction to pull oxygen from the glazes and the clay minerals.[3] For example, luster gets its color from deprivation of oxygen. The reduction agent is a substance from which electrons are being taken by another substance.[3] The reaction uses oxygen from the atmosphere within the reduction tube, and, to continue, it receives the rest of the oxygen from the glazes.[2] This leaves ions and iridescent luster behind. This creates a metallic effect. Pieces with no glaze have nowhere to get the oxygen from, so they take it from clay minerals. This atmosphere will turn clay black, making a matte color.

Reduction firing[edit]


Western raku techniques[edit]





Amongst some of the western raku artists are the French ceramist Claude Champy, who received the Suntory Museum Grand Prix. Sharon Murphy is an American artist specialising in raku fish.[7] Jane Malvisi is a British artist making raku figurines.[8]

Kilns and firing[edit]













Design considerations[edit]

Tea bowl with designs of pine boughs and interlocking circles, unknown raku ware workshop, Kyoto, 18th-19th Century (Freer Gallery of Art)

Raku is a unique form of pottery making; what makes it unique is the range of designs that can be created by simply altering certain variables. These variables—which include wax resist, glazes, temperature, and timing[12]—ultimately determine the outcome when firing a piece of clay. Wax resist, which is painted over the bare untainted clay, results in the suspension of wax in water [13] before the raku glaze goes on. This is done so that the glaze does not cover the area where the wax resist was applied, thus creating a design. When in the kiln, the wax melts off and the carbon, that results from oxygen reduction, replaces the wax.[12] This is the result of the combustion reaction. Raku glazes contain alumina, which has a very high melting point. Therefore, carbon will not replace the glaze as it does the melted wax. Raku glazes also contain metallic compounds such as copper, iron, and cobalt; which produce different colors. After the glaze has reached a certain temperature, the metal in the glaze reacts taking on a specific color.[13] For example, cobalt produces dark-blue, and copper produces green but can also produce a red when the oxygen in the glaze is completely gone.[12] Any unglazed areas turn black due to the carbon given off from the reduction of oxygen. Next, the clay is moved from the kiln to a container, usually a trashcan, which contains combustible organic materials such as leaves, sawdust, or paper. Once the lid of the container is closed, the reduction oxidation (redox) process begins.[13] The temperature change from the kiln to the container is where the magic of raku occurs. The change in temperature and in the redox sometimes cause cracking or crazing. Crazing is a consistent cracking in the glaze of a piece, as is seen on the white crackle glaze. This either enhances or detracts from the design. The timing of removal and placement in water directly affects the shades of each color.[12] Introducing the water to the raku at the right time is incredibly important; if the raku does not cool enough before placement in water, it can crack, break, or even explode.

In literature[edit]

Hiroshi Teshigahara made the film "Rikyu", which is a nearly documentary story showing how Sen no Rikyu met Chojiro, who made the first genuine Raku tea bowl (chawan) and how Rikyu trained the shogun Toyotomi Hideyoshi in the tea ceremony with Raku chawans.(Ashton D 1997).


  • Ashton D: The delicate thread. Teshigahara's life in art. Kodansha Int. Tokyo 1997;150-163.
  • Pitelka, Morgan. Handmade Culture: Raku Potters, Patrons, and Tea Practitioners in Japan. University of Hawaii Press, 2005. ISBN 0-8248-2970-0.
  • Peterson, Susan. The Craft and Art of Clay. The Overlook Press, Woodstock, NY, Second Edition 1996. ISBN 0-87951-634-8.
  • Watkins, James C. Alternative Kilns & Firing Techniques: Raku * Saggar * Pit * Barrel, Lark Ceramics Publications, 2007. ISBN 978-1-57990-455-5, ISBN 1-57990-455-6.
  • Branfman, Steven. "Raku FAQs." Ceramics Today. Ceramics Today, Sept. 2002. Web. 6 May 2010.
  • Herb, Bill. "What Is Raku." Dimensional Design. Bill Herb A.k.a Dimensional Design, Jan. 2000. Web. 6 May 2010.
  • Knapp, Brian J. Oxidation and Reduction. Port Melbourne, Vic.: Heinemann Library, 1998. Print.
  • Birks, Tony. The New Potter's Companion. Englewood Cliffs, N.J.: Prentice Hall, 1982. Print.
  • Rhodes, Daniel. "Special Glazes and Surface Effects." Clay and Glazes for the Potter. Revised ed. Randor: Chilton Book Company, 1973. 318. Print.
  • Zamek, Jeff. "» Glazes: Materials, Mixing, Testing, Firing." » Ceramic Arts Daily – Featured Tip of the Day. Ceramic Publications Company, 5 Nov. 2009. Web. 26 May 2010. <http://ceramicartsdaily.org/ceramic-glaze-recipes/glaze-chemistry-ceramic-glaze-recipes-2/glazes-materials-mixing-testing-firing/?floater=99>.
  • Andrews, Tim " Raku: a review of contemporary work". A.C.Black, London. 1994 ISBN 0-7136-3836-2
  • Andrews, Tim " Raku". A.C.Black, London. 2nd Ed.2005 ISBN 0-7136-6490-8
  • Aguirre, Amber (2012). Naked Fauxku. In Pottery Making Illustrated, Jan/Feb vol 15, p. 40-42.


  1. ^ Byers, Ian (1990). The Complete Potter: Raku. Series Ed. Emmanuel Cooper. B.T. Batsford Ltd 1990, pp. 16. ISBN 0-7134-6130-6
  2. ^ a b c source(Knapp, Brian J. Oxidation and Reduction. Port Melbourne, Vic.: Heinemann Library, 1998. Print.)
  3. ^ a b c d source(Birks, Tony. The New Potter's Companion. Englewood Cliffs, N.J.: Prentice Hall, 1982. Print.)
  4. ^ Arbuckle. "Reduction Firing." Reduction Firing. Web. 6 May 2010. <http://lindaarbuckle.com/handouts/reduction_fire.pdf>.
  5. ^ "Oxidation/Reduction Firing." Frog Pond Pottery. Web. 29 May 2010. <http://www.frogpondpottery.com/pottalk/oxred.htm>.
  6. ^ Branfman, Steven (2001). Raku: A Practical Approach. United States: krause publications. p. 17. 
  7. ^ "Raku Pottery : Ceramic Happy Fish". www.rakufish.com. Retrieved 2015-11-05. 
  8. ^ "Jane Malvisi". www.janemalvisi.co.uk. Retrieved 2015-11-05. 
  9. ^ http://www.studiopottery.com/cgi-bin/mp.cgi?item=9
  10. ^ Warshaw, Josie. The Practical Potter: a Step-by-step Handbook : a Comprehensive Guide to Ceramics with Step-by-step Projects and Techniques. London: Hermes House, 2003. Print.
  11. ^ http://www.koryu.com/library/wbodiford1.html
  12. ^ a b c d Branfman
  13. ^ a b c Herb

External links[edit]