Cloisonne, whose history can date back to over 500 years ago, is well-known traditional enamelware. It is actually called the "Blue of Jingtai" as blue is the dominant color adopted for enameling and cloisonne became prevalent during the reign of Jingtai (1450--1456) in the Ming dynasty. Owing to the brilliant color and splendid designs, cloisonne has been highly appraised at home and abroad. Regarding the making of cloisonne, it involves quite elaborate and complicated processes: base-hammering, soldering, enamel-filling, enamel firing, polishing and gilding.
Procedure of Cloisonne-making
This is, in fact, the work of a coppersmith. As copper is easily hammered and stretched, it is employed to make the body of cloisonne. A sound judgment is required because it determines the uniformity of thickness and weight. In contrast to the work of a coppersmith which is ended when the article is shaped, base-hammering is just the beginning in the making of cloisonne.
The second step can be compared to embroidery, as both require great care and high creativity. The only difference is that instead of embroidering on silk, the cloisonne craftsman adheres copper strips onto the copper body. 1/16 inch in diameter, these strips are shaped into what the artisan requires, usually a complicated but complete pattern. With a blueprint in mind, the craftsman exerts his experience and imagination in setting the copper strips on the body.
Then comes to enamel filling, which requires such basic elements as boric acid, saltpeter and alkaline. Due to the different minerals added, cloisonne appears different in color. Usually one with much iron will turn gray, with uranium, yellow, with chromium, green, with bronze, blue, with zinc, white, with gold or iodine, red. After ores are ground into fine powder and contained in plates, workers apply them on the little compartments separated by filigrees.
Put the article to the crucible and in a moment the copper body will turn red. In time of firing re-filling is repeatedly required, as the enamel in the little compartments will sink down a little after firing.
To make the filigree and the filled compartments even, the artisan has to polish the half finished products again and again. First emery is used. Then after the whole piece is put to fire again, a whetstone is employed for polishing. In the end, a piece of hard carbon is required in order that the article will obtain some luster on the surface.
Lastly, place the article in gold or silver fluid with changing electric current so as to keep the cloisonne free from rust. Another electroplating and a slight polish are demanded for the exposed parts of the filigree and the metal fringes of the article.