Incralac

A protective coating for copper and copper alloys developed in the late 1960s by the International Copper Research Association (INCRA). It contains the corrosion inhibitor benzotriazol (BTA), an acrylic resin, and various other components in an organic solvent (Toluene). It has been tested and used extensively as a surface coating for archaeological and outdoor copper and bronze. It is normally applied by brushing, dipping, or spraying.