Purposefully applied surface deposits or films on bronze sculpture that consist of materials chemically different from the metal substrate. Their composition can vary widely, ranging from natural substances such as lacquer, resin, oil, and wax to synthetic resins. Coatings may be decorative and/or protective. In the study of Renaissance bronzes, for example, applied lacquer-like coatings are often referred to as ‘organic patinas’. Some types of conservation treatment coatings, used in particular to protect outdoor sculptures, are considered sacrificial layers, and require regular maintenance and renewal as they degrade over time.
Note: Not to be confused with corrosion products or mineral compounds bonded to the metal surface, which fall under patina. Though metals were also used to coat surfaces, they are referred to here as plating.
