Sofft Art Sponges are uniquely designed for use with PanPastels and other soft, chalky mediums. This pack contains 4 knives and 8 covers in 4 different shapes: rounded, square, oval and triangle. Attach these sponge covers to the Sofft Knives and use to blend colors like with a brush or palette knife. These gentle, micro-pore sponges are specially designed to evenly distribute delicate colors, without brush strokes. Create unique textures and effects with powdery or water-based mediums. Clean with soap and water, squeeze and air dry fully before reusing.