Marblex is a non-toxic, self-hardening moist gray clay for all methods of modeling including sculpting, coiling, pinching, slabwork, and wheel throwing. Coming prepared in moist form, Marblex is ready to use. Modeled objects are permanent without firing and all air-dried pieces are hard and durable. However, Marblex clay is not waterproof. It will shrink during drying and should never be modeled over a rigid form or armature. Once dry, a Marblex modeled piece can be decorated with different types of finishes, acrylic and tempera paints along with many other mediums. Made in the U.S.A.