Suitable for use on a wide range of materials. Brown for removing surface imperfections on brass, aluminium, pewter and other non-ferrous metals. Black for coarse buffing to remove scratches, rust and corrosion, and to de-burr stainless steel and other hard metals. White can be used on all metals to remove scratches and to obtain a highly reflective finish. Red is for fine polishing of gold, silver and other precious metals.