This clay is a blend of premium epoxy and clay powders resulting in a smooth porcelain like surface that will not shrink when cured. This advanced formula is easy to mix, has a long working time and cures to a hard, durable and impact resistant product. EnviroTex Jewelry Clay® has excellent adhesive qualities and will bond to most surfaces including glass, metal, wood, etc. Once cured, EnviroTex Jewelry Clay® is waterproof, heat and chemical resistant. EnviroTex Jewelry Clay® can be colored while in its uncured form or painted when cured. EnviroTex Jewelry Clay® cures to a firm hardness in 5 hours and full cure in approximately 24 hours at 70° F.