Raku

"Though you wipe your hands and brush off the dust and dirt from the vessels, what is the use of all this fuss if the heart is still impure?" Sen-No-Rikyu

Rakuyaki (樂焼き) or Raku (樂) is a form of Japanese pottery characterized by low firing temperatures (resulting in a fairly porous clay 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 clay bowls for the Japanese tea ceremony. Raku tea bowls are hand-made from earthenware, each with a unique shape and style.

The term raku is derived from the Chinese 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.

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 Koyatusu (1556-1637) and Ogata Kenzan (1663-1743).

Western Raku Techniques

The use of a reduction chamber at the end of the raku firing was introduced by the American potter Paul Soldner in the 1960s. 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 clay surface with carbon. This last step in the process is unique to the Western form of raku. Western raku potters rarely use lead as a glaze ingredient, due to its serious level of toxicity. Glaze recipies which craze (present a cracked appearance) are often used, as the crazing lines take on a dark color from the carbon as well.

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). The process is known for its unpredictability, particularly when reduction is forced. Pots may be returned to the kiln to re-oxidise if firing results do not meet the potter's expectations. The firing times for raku ware are short, perhaps three hours total, as opposed to up to 16 hours for stoneware firings. This is primarily due to the rapid temperature changes during the process. Raku also eliminates the slow cooling time required in enclosed kilns. As a result of these variations in temperature, clays 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 sand or 'grog' (prefired clay that has been finely ground) into the clay before the pot is formed. Most porcelains and white stoneware clay bodies are unsuitable for the Western raku process.

Reference

• 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.

External link

• Raku museum Kyoto (http://www.raku-yaki.or.jp/)
• e-yakimono.net (http://www.e-yakimono.net/guide/html/raku-yaki.html)de:Raku-Keramik