Black chrome (rack) is a black chrome plating that combines both decorative and functional properties. Unlike conventional bright chrome plating, it forms a matte black film with suppressed gloss by using a chromic acid bath containing special additives and electroplating at a low current density. Because this film has excellent low reflectivity, it is widely used for optical instrument components, camera parts, and measuring instrument housings, among others. Furthermore, because it also excels in corrosion resistance and wear resistance, its properties are utilized in a wide range of fields, including automotive interior and exterior parts, home appliances, building materials, and decorative items. The film thickness is typically several micrometers, and it is ideal for applications requiring a uniform black appearance and high durability.