Self hardening artist clay for school home arts and crafts. Safe multi-purpose and economical. Just like other clay Mexo Self hardening clays are great for modeling throwing sculpting and thousands of crafting and hobby projects. The cure for shrinking school budgets Mexo's self-hardening formula saves the hassle and expense of kiln firing while producing a finished product which dries leather hard in 24 hours and rock hard within several days (actual drying time varies with temperature humidity and thickness of clay). Decorate with acrylic paints. Must be sealed with a commercial water sealant to waterproof.