The BlueSpot 4 PCE Buffing Compound Set contains 56g of each type and is suitable for use on a wide range of materials. The tripoli (brown) buffing compound is ideal for removing surface imperfections on brass, aluminium, pewter and other non-ferrous metals. The emery (black) buffing compound is for coarse buffing to remove scratches, rust and corrosion, and to de-burr stainless steel and other hard metals. The white buffing compound can be used on all metals to remove scratches and to obtain a highly reflective finish. The jewellers' (red) buffing compound is for fine polishing of gold, silver and other precious metals.