Vitreous enamel, the kind of enamel used on metal, is a substance of powdered glass fired on metal. The art of enameling dates back to the ancient Egyptians who applied enamels to pottery, stone, decorative items, household items, and jewelry. The ancient Greeks, Chinese, Celts and Georgians also practiced the art of enameling. Vitreous enamel can be applied to most metals; stainless steel, copper, cast iron, gold, silver and aluminum can be used as substrates. Enamel’s desired properties, such as smoothness, hardness, durability, high scratch resistance, and resistance to fading makes it ideal for large industrial uses, from cooking items to large storage structures. Cloisonné, where colorful enamel is separated by thin steel, is still produced today, mainly in China.