Activa's Model N' Mold is reusable and non-toxic, with natural color and waterproof properties. This enables the creation of landscapes and models, be painted, and support water such as a river, lake, or moat. Suited for fast dimensional studies, an introductory carving material, as well as producing molds for sand casting. Mold N' Mold is special sand designed for creative use indoors or out.