Soft, grit-free, molded chalk features an intensely rich, colorful & smooth laydown on paper, cardboard & other smooth or toothed surfaces. They blend easily for an array of colors. Versatile chalk works well on wet or dry mediums. Use them for posters, murals, stage props, sketching & other art projects. They are not recommended for chalkboards. Flake chalk into water for a unique marbling effect. PMA-certified, nontoxic construction is safe for children.