ARMADILLO ART AND CRAFT-Sofft Art Sponge. These sponges are designed to be used with PanPastel artist's pastels but can also be used with water-based colors, polymer clays, and ceramics. They are artist's quality with Micropore technology and can be cleaned and reused on all your projects. This package contains four 2 inch diameter, 1/4 inch thick sponges.