This self-hardening, nontoxic modeling compound is soft, clean and easy to use. Ideal for a wide range of hands-on learning projects and sculpting activities. 1-oz. packs give teachers control over the quantity given out in the classroom; less waste. Air-dries to a smooth, resilient finish, usually within 24 hours. The compound can be colored with Crayola paint or markers (not included). Clay/Pottery Type: N/A; Color(s): Assorted; Age Recommendation: Ages 5 and Up; Assortment: 21 White; 18 Blue; 18 Red; 18 Yellow.