POLYFORM-Non-hardening and reusable modeling clay! Contains 13 ounces of clay in 20 colors. EZ Shape Modeling Clay is the perfect medium to build creativity. It is a pigmented wax-base sculpting medium that has a smooth texture and a full range of bright colors. It stays pliable, will never harden, and it adheres to itself for easy modeling. For ages 4 and up. Non-toxic. Lead free. Conforms to ASTM D4236. Caution: Will not harden in oven-Do not bake! Caution: Modeling clays contain ingredients that may stain or damage finished surfaces.