Clayette Soft Clay is sulfur-free, nonhardening, odor-free and flexible without being sticky. Clayette will not oxidize and can be left out or heated and cooled repeatedly without any significant change in the product. Clayette will not melt when heated over 300°F. Using small amounts of citrus-based solvents, lighter fluid, turpentine or mineral spirits as a lubricant on the surface of the clay will help to attain a smooth surface. Clayette is similar to the original Klean Klay. This clay is sold in 900gm blocks.