Catalyst Contours - Ideal for oils, acrylics and water-miscible oils, these contour tools are made out of nylon and silicone that is heat-resistant, solvent-resistant, dishwasher-safe and approved food-safe by the FDA. They work well with plaster, clay, encaustics, ceramics, cake decorating and food crafting. The silicone is easy to wipe clean and is solvent resistant. Clean up in most cases can be done with mild soap and water. Dried paint can be peeled off the silicone surface.