What is Raku?
Raku, is a firing technique that is traditionally used in the Japanese Tea Ceremony most often in the form of tea bowls. It traces its rich history to a process that originated in Japan in the 16th century. The technique involved removing red-hot, carved, clay pieces from a wood-fired kiln and placing them on the ground to cool. This unusual approach produced simple, stone-like cups and bowls that were used in rituals related to the tea ceremonies.
A little bit of History
After a long period of isolation from the 17th to the mid-19th century, Japan resumed trade with the West in 1853, and Japanese goods soon began to pour into Europe.
A wealth of visual information from the superb Japanese traditions of ceramics, metalwork, architecture, printmaking, and painting reached the West and brought with it electrifying new ideas of composition, color, and design; Japanese arts became the sensation in Europe and America throughout the late 19th and early 20th centuries.
But it was not until the 20th century that Raku came into view. Many of the most influential collectors and potters of the time started to attend open sessions at the English pottery studio of Bernard Leach, a British potter who brought the Raku concept to the west in 1911.
From then on, Western potters began to appreciate and emulate the Zen pottery aesthetic inherent in Raku. Thus began an evolutionary process that fused Eastern and Western aesthetic philosophies during the next five decades.
In the first half of the 1960’s, an American artist named Paul Soldner would radically expand the boundaries of Raku. He broke with tradition by using more colorful glazes, developing new post-firing reduction techniques and producing shapes embodying the sculpture of the day.
His groundbreaking work lead to the development of the modern Raku process that is used by virtually all western ceramic artists today.
Raku then and raku now
Raku pottery is traditionally characterised by being hand shaped rather than thrown, which gives it a slightly irregular shape. Most have a small, round foot and sides that are almost straight except for small indentations about halfway from the top. Originally raku bowls were undecorated and modest in shape. The smaller size helped them fit the hand and convey the warmth of the tea.
Raku bowls were generally fairly porous vessels, which resulted from low firing temperatures, lead glazes and the removal of pieces from the kiln while still glowing hot. And that is exactly where the traditional Japanese process stops; the fired raku piece removed from the hot kiln and cooling in the open air. Contemporary potters worldwide have modified this thechnique by placing the pottery - after removal from the kiln - into the containers for reduction.
During the extreme temperature change of removing it from the kiln - with a temperature of approximately 1000°C - into the open air, crazing or cracking occurs on many of the glazed areas on the pots. The still glowing pot is then placed into an airtight container, a "reduction chamber", filled with sawdust and old newspapers.
The reduction or carbonization process begins once the red hot pots ignite the combustible materials. As soon as the materials ignite, the containers are closed, thus creating a totally smoke filled atmosphere inside. This intense reduction atmosphere effects the colors in glazes and clay bodies; any unglazed areas, including the cracks in the glaze, will turn black from the smoke. Many variables in the process, including timing and the degree of thermal shock, create random fissures and variations of colour.
After about 15 minutes, the pottery (often still over 600ºC) may then be plunged into cold water to halt the process. The final phase of the raku process is the cleaning; cleaners, toothbrushes, and scouring pads, have to be used to scrub clean, all glazed areas.