Cloisonne - The Art of Decorative Enameling
Cloisonné, an ancient metalworking technique, is a multi-step enamel process used to produce jewelry, vases, and other decorative items. It first developed in the Near East then spread to the Byzantine Empire and from there along the Silk Road to China. At that time, the Chinese nation possessed excellent conditions for developing cloisonn| enameling art--it already had metallurgical technology, such as bronze casting; glass and glaze production techniques were well-known; and how to accurately control the firing temperature was already understood.
An exquisite piece of cloisonné must have colors that are moist and glossy, fresh and bright, a body that is substantive and sturdy, a wire inlay that is neat and well-proportioned, and gold plating that glitters.
How to make Cloisonné
Body-making
the artist forms metal (such as copper, bronze, or silver) into the shape of the finished object. The material usually used for making the body is copper, since it is easily hammered and stretched.
Filigree-soldering
which is pure silver wire usually about .010 x .040 inches in cross section, is bent into shapes that define the colored areas. The bends are all done at right angles, so that wire does not curve up. This is done with small pliers, tweezers, and custom-made jigs.
Enamel-filling
Enamel was made by melting different materials such as red lead, boric acid borate, and glass powder together to become an opaque or translucent glistening substance. A variety of oxidized metals are added, and the substance then changed into enamels of different colors, or enamel coloring.
Enamel-firing
This is done by putting the article, with its enamel fillings, to the crucible. After firing, the enamel would contract, producing an uneven surface. It was then necessary to fill in the uneven places with enamel paste of the same color many times over. This procedure had to be repeated many times until every filled-in space became thoroughly smooth without any depressions.
Polishing
Some pieces of hard carbon are used for polishing to produce some lustre on the surface of the article.
Gilding
The exposed brass wires between parts of the patterns as well as the rim and the bottom of an object, to which enamel had no been applied, were gold plated.
http://en.wikipedia.org/wiki/Cloisonne
