Metal finishing usually involves a combination of metal cleaning operations, metal deposition operations and numerous finishing operations. The materials include solvents and surfactants for cleaning, acids and bases for etching, and solutions of metal salts and other compounds to plate a finish onto a substrate. Physical, chemical and electrochemical processes are all used to finish metal workpieces. The processes may simply polish the surface to provide a bright appearance or apply another metal to change the surface properties or appearance.