Cloisonné enamel
Cloisonné (French pronunciation: [klwazɔne]) is an ancient technique for decorating metalwork objects. In recent centuries, vitreous enamel has been used, and inlays of cut gemstones, glass and other materials were also used during older periods. The resulting objects can also be called cloisonné. The decoration is formed by first adding compartments (cloisons in French) to the metal object by soldering or affixing silver or gold wires or thin strips placed on their edges. These remain visible in the finished piece, separating the different compartments of the enamel or inlays, which are often of several colors. Cloisonné enamel objects are worked on with enamel powder made into a paste, which then needs to be fired in a kiln.
In antiquity, the cloisonné technique was mostly used for jewellery and small fittings for clothes, weapons or similar small objects decorated with geometric or schematic designs, with thick cloison walls. In the Byzantine Empire techniques using thinner wires were developed to allow more pictorial images to be produced, mostly used for religious images and jewellery, and by then always using enamel. By the 14th century this enamel technique had spread to China, where it was soon used for much larger vessels such as bowls and vases; the technique remains common in China to the present day, and cloisonné enamel objects using Chinese-derived styles were produced in the West from the 18th century.
Cloisonné first developed in the jewellery of the ancient Near East, typically in very small pieces such as rings, with thin wire forming the cloisons. In the jewellery of ancient Egypt, including the pectoral jewels of the Pharaohs, thicker strips form the cloisons, which remain small. In Egypt gemstones and enamel-like materials sometimes called "glass-paste" were both used. The Byzantines perfected a unique form of cloisonné icons. Byzantine enamel spread to surrounding cultures and a particular type, often known as garnet cloisonné is widely found in the Migration Period art of the "barbarian" peoples of Europe, who used gemstones, especially red garnets, as well as glass and enamel, with small thick-walled cloisons. Red garnets and gold made an attractive contrast of colours, and for Christians the garnet was a symbol of Christ. This type is now thought to have originated in the Late Antique Eastern Roman Empire and to have initially reached the Migration peoples as diplomatic gifts of objects probably made in Constantinople, then copied by their own goldsmiths. Glass-paste cloisonné was made in the same periods with similar results – compare the gold Anglo-Saxon fitting with garnets (right) and the Visigothic brooch with glass-paste in the gallery. Thick ribbons of gold were soldered to the base of the sunken area to be decorated to make the compartments, before adding the stones or paste. Sometimes compartments filled with the different materials of cut stones or glass and enamel are mixed to ornament the same object, as in the Sutton Hoo purse-lid. In the Byzantine world the technique was developed into the thin-wire style suitable only for enamel described below, which was imitated in Europe from about Carolingian period onwards.
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