This quality modeling clay never hardens making it a great material for artists. It remains pliable and plastic and can be used time and time again. It is used by sculptors, model makers, clay animators, and artists of all ages. Streaking may occasionally occur during the color formulation process, and can be dissolved as the clay is worked by hand. Please note: not oven bake clay.Details:Available in assorted colors1 lb. (453 g)Self-adheringNon-toxicNon-hardening and reusableSulfur free