Cloisonne is an enameling technique in which thin metal strips are fixed to a base to form small cells, called cloisons (French for "partitions"). Each cell is filled with powdered glass enamel and fired until the glass melts and fuses. The finished surface shows areas of color separated by fine metal lines, a look used in jewelry, religious objects and decorative vessels for well over a thousand years.
What enamel is
Vitreous enamel is glass ground to a powder, colored with metal oxides, and fused to metal at high temperature. Different oxides give different colors: cobalt for blue, copper for green or turquoise, and gold compounds for some reds and pinks. Enamels can be transparent, translucent or opaque. Enamel fuses best to metals that do not oxidize badly when heated, which is why fine silver, high-karat gold and copper are the usual bases. Gold is the most forgiving of the three.
How cloisonne is made
The process has changed little in its broad outline:
- The base piece is shaped from metal sheet, often copper for larger objects and gold or fine silver for jewelry.
- Thin flat wire or ribbon is bent into the outlines of the design.
- The wires are attached to the base, either with solder or by setting them into a first thin layer of enamel.
- Each cell is filled with wet enamel powder of the chosen color.
- The piece is fired in a kiln, usually around 750 to 850 degrees Celsius depending on the enamel.
- Enamel shrinks as it melts, so the cells are refilled and fired several times until the enamel is level with the wire tops.
- The surface is ground flat with stones and then polished, which exposes the metal lines.
- A final light firing or polishing gives the surface its gloss, and larger copper pieces are often gilded on the exposed metal.
Firing has to be judged carefully. Underfired enamel looks grainy, while overfired enamel can burn, change color or pull away from the wires.
Byzantine cloisonne
Cloisonne appears in the eastern Mediterranean in antiquity, and the earliest examples include small cells filled with cut stones rather than glass. The technique reached a peak in the Byzantine Empire, especially from around the 9th to the 12th centuries. Byzantine enamelers worked mostly in gold and used two methods: full enamel, where the whole surface is covered, and sunken enamel, where figures sit in a recessed area surrounded by plain gold.
The work was used on reliquaries, book covers, icons, crowns and jewelry. The Pala d'Oro altarpiece in St Mark's Basilica, Venice, holds a large group of Byzantine enamel plaques. Medieval jewelry across Europe borrowed from Byzantine work, and Western workshops produced their own enamels in the following centuries.
Garnet cloisonne
A related form uses cut stones instead of glass. Early medieval goldsmiths in Europe set thin slices of garnet into gold cell-work, sometimes over patterned gold foil that reflected light back through the stone. The Anglo-Saxon finds from Sutton Hoo in England are famous examples. The stones in this work are usually almandine or pyrope; see almandine garnet.
Chinese cloisonne
Cloisonne reached China by about the 14th century, and Chinese workshops developed it into a major art. Production flourished under the Ming dynasty, with the reign of the Jingtai emperor in the 15th century so closely tied to the work that the Chinese name, jingtailan, refers to it. Qing dynasty workshops in the 18th century produced large quantities for the court.
Chinese cloisonne is usually on copper or bronze, with opaque enamels and gilded wires. Turquoise blue grounds are typical. It was used on vases, incense burners, boxes and furniture fittings as well as on hairpins and other ornaments, and it was exported in large numbers from the 19th century. Japanese makers took up the technique in the 19th century and became known for very fine wirework and for wireless cloisonne, in which the wires are removed before the last firing. For the wider tradition, see jewelry of East and Southeast Asia.
Comparing cloisonne, champleve and plique-a-jour
Three enamel methods are often confused. The difference lies in how the cells are made.
| Technique | How the cells are formed | Look |
|---|---|---|
| Cloisonne | Wires attached to a flat base | Fine metal lines between colors |
| Champleve | Recesses carved, etched or cast into the metal | Broader metal areas, enamel sits in hollows |
| Plique-a-jour | Cells with no backing, like a tiny stained-glass window | Translucent, light passes through |
Champleve was widely used in medieval Europe, with Limoges in France a major center from the 12th century. Plique-a-jour is technically demanding because the enamel must hold in open cells, often fired on a temporary backing that is later removed. It was a favorite of Art Nouveau jewelry designers such as Rene Lalique.
Other enamel styles include basse-taille, where translucent enamel covers an engraved or chased surface, and painted enamel, where the image is painted on with enamel colors.
Care of enamel jewelry
Enamel is glass, so it can chip or crack if knocked or bent, and it does not tolerate sudden temperature changes. Clean it with a soft cloth and mild soapy water, avoid ultrasonic cleaners, and keep it away from hard surfaces. Repairs are possible but require refiring or cold enamel fills, which a specialist should judge. The jewelry cleaning guide covers general care, and the page on how jewelry is made puts enameling in context with other workshop methods.
Frequently asked questions
What does cloisonne mean?
The word comes from the French cloison, meaning partition. It refers to the small cells formed by metal wires that hold the enamel.
Is cloisonne made of glass?
Yes. The colored areas are vitreous enamel, a powdered glass fused to the metal in a kiln.
What is the difference between cloisonne and champleve?
In cloisonne the cells are built up with wires on a flat surface. In champleve the cells are carved, etched or cast down into the metal.
Can cloisonne jewelry go in an ultrasonic cleaner?
It is better not to. Vibration and heat can crack enamel, so a soft cloth and mild soapy water are safer.