Copper coatings, also known as PATINAS, are a type of protective coating applied to copper surfaces to protect them from corrosion and oxidation. PATINAS are formed when copper is exposed to air and moisture, creating a thin layer of copper oxide on the surface. This layer helps to protect the underlying copper from further damage. PATINAS can also be artificially created by applying chemicals or heat to the copper surface. PATINAS can range in color from green to blue to black, depending on the type of patina used.