This clay has been formulated to withstand the thermal shock of Raku firing. It has a heavy sand content yielding a coarse texture. Suited for either handbuilding or wheel throwing. Raku is an ancient method of firing pottery which originated in Japan centuries ago. It evolved in conjunction with the philosophy of Zen Buddhism and developed as an important part of the traditional Japanese tea ceremony. Briefly, the process involves the application of glaze to a bisque-fired pot, which is then placed in a preheated kiln. When the glaze melts, (about Cone 06), the pot is removed and placed in a container with combustible material. The container is covered and the pot is allowed to reduce for a while, then it is removed and sometimes submerged in a bucket of water to cool. The effects created by the smoky atmosphere are usually unpredictable but exciting. Characteristics Approx. Cone: 06 Wet Color: Light Gray Fire Color Oxidation: Buff Reduction: N/A Texture: Coarse Penetrometer Target: 7 Avg. Shrinkage 2±% 6% Avg. Water Absorption 1±% 16% COE x 10-6: 4.25