A 16th century black Raku-style chawan, used for thick tea (Tokyo National Museum)

Rakuyaki (樂焼き) or Raku (樂) is a form of Japanese pottery characterized by low firing temperatures (resulting in a fairly porous body), lead glazes, and the removal of pieces from the kiln while still glowing hot. In the traditional Japanese firing process, the pot is removed from the hot kiln and put directly into water or allowed to cool in the open air. Raku is considered the traditional method for creating bowls for the Japanese tea ceremony. Raku tea bowls are hand-made from earthenware, each with a unique shape and style. Image File history File links Download high resolution version (660x707, 102 KB) Black Raku Tea Bowl, Kuroraku type, Raku Ware, Known as Amadera, Studio of Chojiro, Azuchi-Momoyama period, 16th century (Gift of Mr. ... Image File history File links Download high resolution version (660x707, 102 KB) Black Raku Tea Bowl, Kuroraku type, Raku Ware, Known as Amadera, Studio of Chojiro, Azuchi-Momoyama period, 16th century (Gift of Mr. ... The Azuchi-Momoyama period (Japanese: 安土桃山時代, Azuchi-Momoyama-jidai) is a division of Japanese history running from approximately 1568 to 1600. ... The Tokyo National Museum. ... According to archeological evidence, Japanese pottery is among the earliest in the World, dating back to the 11th millennium BC, marking the beginning of the Jomon period. ... General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish white Atomic mass 207. ... Glaze is a thin shiny coating, or the act of applying the coating. ... Charcoal Kilns, California Gold Kiln, Victoria, Australia Hop kiln. ... A woman wearing a kimono performs a tea ceremony outdoors, while seated in seiza position. ... A 16th century black Raku-style chawan, used for thick tea (Tokyo National Museum) A chawan (茶碗) is a bowl used for preparing and drinking matcha (powdered green tea) in Japanese tea ceremonies. ... Earthenware is a particularly common type of ceramic material and is used extensively for tableware and decorative objects. ...

The term raku is derived from the Kanji character meaning "enjoyment" or "ease". For fifteen generations, it has been the title and seal used by a dynasty of potters whose work formed the central tradition of Japanese raku. In the 16th century, the first of these potters, Chojirō (長次郎), came under the patronage of the Japanese tea master Sen-No-Rikyu. In 1598, the ruler Hideyoshi bestowed the name Raku on Chojirō after he began making tea bowls to the great tea master's specifications. Upon the death of Chojirō in 1592, his son Jokei continued the raku tradition. Both the name and the ceramic style have been passed down through the family to the present. Japanese writing Kanji Kana Hiragana Katakana Hentaigana Manyogana Uses Furigana Okurigana Rōmaji Kanji (Japanese: ) are the Chinese characters that are used in the modern Japanese logographic writing system along with hiragana (平仮名), katakana (片仮名), and the arabic numerals. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Hideyoshi at his old age. ...

Raku ware marked an important point in the historical development of Japanese ceramics. With the formal recognition of raku potters in the late 16th century, the Japanese artist-potter first emerged from the anonymity of the general craftsman. Other famous Japanese clay artists of this period include Donyu (1574-1656), Hon'ami Kōetsu (1556-1637) and Ogata Kenzan (1663-1743). Honami Kōetsu (本阿弥光悦)(1558-1637) was a Japanese craftsman, potter, lacquerer, and calligrapher, whose work is generally considered to have inspired the founding of the Rinpa school of painting. ... Ogata Kenzan (尾形 乾山, 1663 - 1743), originally Ogata Shinsei, and also known by the pseudonym Shisui, was a Japanese potter and painter. ...

Western raku techniques

A vase glazed and fired using the Western Raku technique, showing the soot, crackle glazing, and random oxidation typical of this pottery technique.

The use of a reduction chamber at the end of the raku firing was introduced by the American potter Paul Soldner in the 1960s, in order to compensate for the difference in atmosphere between wood-fired Japanese raku kilns and gas-fired American kilns. Typically, pieces removed from the hot kiln are placed in masses of combustible material (e.g., straw, sawdust, or newspaper) in order to provide a reducing atmosphere for the glaze, and to stain the exposed body surface with carbon. Image File history File links Western-raku-vase. ... Image File history File links Western-raku-vase. ... The most fundamental reactions in chemistry are the redox processes. ... Paul Soldner (b. ... Straw is the dry stalk of a cereal plant, after the nutrient grain or seed has been removed. ... Sawdust is composed of fine particles of wood. ... A reducing environment is one chacterized by little or no free oxygen (dissolved or as a gas). ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ...

Western raku potters rarely use lead as a glaze ingredient, due to its serious level of toxicity. Although almost any low-fire glaze can be used, potters often use specially formulated glaze recipes that "crackle" or craze (present a cracked appearance), because the crazing lines take on a dark color from the carbon.

Western Raku is typically made from a stoneware clay body, bisque fired at 900°C (1650°F) and glaze fired (the final firing) between 800-1000°C (1450-1800°F), which falls into the cone 06 firing temperature range. The process is known for its unpredictability, particularly when reduction is forced, and pieces may crack or even explode due to thermal shock. Pots may be returned to the kiln to re-oxidize if firing results do not meet the potter's expectations, although each successive firing has a high chance of weakening the overall structural integrity of the pot. Pots that are exposed to thermal shock multiple times can break apart in the kiln, as they are removed from the kiln, or when they are in the reduction chamber. Stoneware is a category of clay and a type of pottery distinguished primarily by its firing and maturation temperature (from about 1200°C to 1315°C). ...

The glaze firing times for raku ware are short, an hour or two as opposed to up to 16 hours for high-temperature cone 10 stoneware firings. This is due to several factors: raku glazes mature at a much lower temperature (under 1800°F, as opposed to almost 2300°F for high-fire stoneware), kiln temperatures can be raised rapidly, and the kiln is loaded and unloaded while hot and can be kept hot between firings.

Because temperature changes are rapid during the raku process, bodies used for raku ware must be able to cope with significant thermal stress. The usual way of dealing with this is to incorporate a high percentage of quartz, Grog (prefired clay that has been finely ground), or Kyanite into the body before the pot is formed. Each of these materials is used to add strength to the clay body and to reduce thermal expansion. When used for over 10% of the clay body, quartz can cause dunting or shivering therefore, Kyanite is often the preferred material because it contributes both mechanical strength and, in amounts up to 20%, it significantly reduces thermal expansion. Although any clay body can be used, most porcelains and white stoneware clay bodies are unsuitable for the Western raku process unless some material is added to deal with thermal shock. Grog (also called firesand) is a type of pre-fired clay that has been ground and screened to a specific particle size. ... Kyanite, whose name derives from the Greek, kyanos, meaning blue, is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. ... Glaze Defects are any flaws in the surface quality of a Glaze, its physical structure, or its interaction with the clay body. ... Glaze Defects are any flaws in the surface quality of a Glaze, its physical structure, or its interaction with the clay body. ... Kyanite, whose name derives from the Greek, kyanos, meaning blue, is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. ...

References

• Pitelka, Morgan. Handmade Culture: Raku Potters, Patrons, and Tea Practitioners in Japan. University of Hawaii Press, 2005.
• Hamer, Frank and Janet. The Potter's Dictionary of Materials and Techniques. A & C Black Publishers, Limited, London, England, Third Edition 1991. ISBN 0-8122-3112-0.

• Peterson, Susan. The Craft and Art of Clay. The Overlook Press, Woodstock, NY, Second Edition 1996. ISBN 0-87951-634-8.

See also

• Chawan

A 16th century black Raku-style chawan, used for thick tea (Tokyo National Museum) A chawan (茶碗) is a bowl used for preparing and drinking matcha (powdered green tea) in Japanese tea ceremonies. ...

External links

• Raku museum Kyoto
• e-yakimono.net
• Raku Glaze Recipes