Cloisonn is a multi-step enamel process used to produce jewelry, vases, and other decorative items. Objects produced by this process are also called cloisonn .

Adding cloisons according to the pattern previously transferred to the workpiece

Detail showing pattern and partially completed cloisons

Adding frit with dropper after sintering cloisons. Upon completion the piece will be fired, then ground (repeating as necessary) then polished and electroplated

Cloisonn process

• First, a metal such as copper or brass is formed into the shape of the finished object.

• A paper pattern and a pencil is used to transfer a design to the metal object.

• Partitions (French cloisons) that act as color separators are applied according to the transferred pattern and are held in place by a soldering paste (this is finely divided metal of low melting temperature in a flux paste). The partitions are bent and cut to length from flat wire stock, usually by hand using simple pliers while the paste is applied with a small brush.

• The partitions are permanently affixed to the base metal by heating the piece in an oven, which melts the solder, then the piece is cooled.

• Glass frit in a water based paste is painted into the partitions using an annotated pattern similar to the "paint by numbers" craft technique. The frit is dried and is then melted onto the metal by firing in an oven. This is repeated several times to build up the coatings to the height of the partitions. Various colors and transparencies may be used in combination within a single partition to obtain a desired artistic effect.

• The glass and a portion of the cloisons are ground and polished to form a even and smooth surface.

• The exposed metal is electroplated with a thin film of gold to prevent corrosion and for a pleasing appearance.

History and an early Chinese example

Chinese Imperial Queen's headdress of the Ming dynasty, ca 1400 C.E.

Cloisonn is an ancient metalworking technique, first developed in the Near East. It spread to the Byzantine Empire and from there along the Silk Road to China, now the site of many high quality production facilities.

This example, an Imperial Queen's headress, contains leaf patterns in a single light blue color with each element is bounded by a rim, making this a work with cloisonne rather than simply enameled copper.

Other examples

• The Pala d'Oro, Saint Mark's Cathedral, Venice

• The Alfred Jewel, a 9th century English jewel

Contrast Champlev enamel

See also

• Vitreous enamel