Vitreous enamel, also called porcelain enamel, is a material made by fusing powdered glass to a substrate by firing, usually between 1,380°F and 1,560 °F. The powder melts, flows, and then hardens to a smooth, durable vitreous coating.
The earliest known enamelled objects were made in Cyprus in around the 13th century BC during the Mycenæan period. Six gold rings discovered in a Mycenæan tomb at Kouklia were decorated with various vitreous coloured layers fused on to the gold.
Earlier decoration of metal objects with glass, along with other materials such as precious and semi-precious stones, such as those found in the tombs of ancient Egypt relied on cementing the glass to the metal or a mechanical fixing by clasps. It was not until this unknown craftsman in Cyprus discovered that by fusing the glass on to the metal that the art of vitreous enameling was born.