Film on metal is a process in which a thin layer of film is applied to a metal surface. The film is usually composed of a polymeric material, such as a plastic or a resin, and is used to protect the metal from corrosion and wear. The film can also be used to enhance the appearance of the metal, such as by adding a PATINA, which is a thin layer of color or texture that gives the metal a unique look. PATINA is a term used to describe the natural aging process of metals, which can be accelerated through the application of a film.