Coating on metal surface layer or layers of enamel, by firing, they react and strong combination of composite materials. Old enamel. Inherent mechanical strength and workability of the metal, and coated with corrosion-resistant, wear-resisting, heat-resisting, nontoxic and decorative. Enamel comes from glass to metal. Ancient Egypt appeared first, followed by Greece. 6th century European embedded wire enamel, picking flower enamel, enamel, translucent enamel, painted enamel relief appearance. In 8th century China began development of enamel, enamel art matured in the late 14th century, middle of 15th century during the reign of jingtai of Ming dynasty products are particularly known for a cloisonne said. Early 19th century cast iron enamel has been developed in Europe, laid the groundwork for enamel from handicrafts to daily necessities, but due to casting technology, cast iron enamel application is limited. In the 19th century, the development of various types of industrial, enameled steel, creating a new era of modern enamel. ~20 century in the late 19th century, the advent of different enamel, steel and other metals used, refractories, furnaces, painted enamel technology continues to update, to speed up the development of enamel industry.