enamels
ɪˈnam(ə)l
noun
an opaque or semi-transparent glossy substance that is a type of glass, applied by vitrification to metallic or other hard surfaces for ornament or as a protective coating.
pieces of metalwork decorated with enamel
verb
coat or decorate (a metallic or hard object) with enamel.
he enamelled the back of the case in the rococo style