Activa Plus Clay 2.2 lb. Black Plus Clay is a premium quality self-hardening natural clay with exceptional plasticity and ultra-fine grade that allows for excellent detail. Once dry Plus Clay has superior strength and durability. Plus Clay is suited for a wide range of techniques and applications including: hand building wheel throwing extrusion sculpture casting structural ceramics model making and tile making. Plus Clay can be carved sanded and drilled when dry and it will accept virtually any finish.