In a discussion of art technology, enamel (or vitreous enamel, or porcelain enamel in American English) is the colourful result of fusion of metals carried in powdered glass to a substrate through the process of firing, usually between 750C and 850C. The powder melts and flows to harden as a smooth, durable vitreous coating on metal, glass or ceramic. It is often applied in a paste form and may be transparent or opaque when fired. Vitreous enamel can be applied to most metals.
Vitreous enamel has many excellent properties: it is smooth, hard, chemically resistant, durable, can take on long-lasting, brilliant colours, and cannot burn. Disadvantages are its tendency to crack or shatter when the substrate is stressed or bent.
Low firing enamels formulated for glass are forms of paint designed to fire between 550C and 600C which avoids the distortion of the glass that would occur with enamels designed for metals.