Enamel
The vitreous enamels used on silver are formed from coloured glass which is ground extremely fine and applied to the silver surface prior to firing and melting in a kiln. The fired surface may be sanded down and refired several times until the desired effect is reached. The vivid colours of vitreous enamels are permanently bonded to the silver surface and are not to be compared with cheaper products where the "enamel" is merely a plastic layer on the surface.