Knife & Covers: When using the knife with Sofft Covers, this tool functions as a cross between a brush and a knife. Sofft Knives are made from flexible and durable plastic material. The covers are made from semi-absorbent micropore material. Simply wash the covers with soap and warm water, squeeze and air dry for reuse. Apply, blend and manipulate PanPastel colors with this nifty tool. Perfect for polymer clay. The applicators are great for softening hard edges, blending colors and applying colors in hard to reach areas. The sponges can be used for backgrounds and underpainting, double and triple loading colors, building up smooth layers and blending and manipulating colors