Enameling is also known as Fused Glass on Metal. Enameling is characterized by brilliant, non-fading colors, tremendous durability, variety of color effects depending on angle of light, and tremendous versatility – from jewelry (many people are familiar with cloisonne, which is a type of enameling), to bowls and wall pieces, to large-scale interior or exterior murals. The medium of enameling goes back two thousand years and forms part of the artistic heritage on six continents.
Vitreous enamels are finely ground glass, like fine sand (or even more finely pulverized and mixed with an oil or adhesive). They may be opaque or transparent; their colors come from the use of various oxides. The surface quality of enamel can vary from a high gloss to a matte or dull finish. The color quality of enamel is heightened as light goes through the glass material and reflects back from the metal base through the color, especially when using translucent or transparent colors.
The enamel is applied on metal, usually copper, gold, silver, or pre-coated iron or steel, and then fired in a furnace or with hand held torch. Although enamel takes only a few minutes to fuse, each color must be fired separately between 1350-1500° Fahrenheit, which means that most enamel art pieces have been fired at least six times, and sometimes as many as 30 or more.
Enamels also must be “countered” (balanced) on the back for two reasons: to avoid excess warping and hence glass cracking, and also to avoid fire-scale. Every time metal is put into the kiln at such a high temperature, it burns and creates a black, flaky substance known as fire-scale. Not only is it messy, but it eventually weakens and destroys the metal. In between each firing, the artist must file all exposed edges to avoid black flakes contaminating the pristine environment of each separate enamel color.
In working with the enamels various techniques can be used. Enamels may be sifted, painted, stencilled, sponged, dropped, or inlaid wet or dry on the metal. Further effects can be obtained by use of sgraffito, etching the metal, inlaying metal paillons, and/or high-firing. Experimental techniques such as raku-firing are also used.