Byzantine enamel

The craft of cloisonné enameling is a metal and glass-working tradition practiced in the Byzantine Empire from the 6th to the 12th century. The Byzantines perfected an intricate form of vitreous enameling, allowing the illustration of small, detailed, iconographic portraits.

The development of the Byzantine enamel art occurred between the 6th and 12th centuries. The Byzantines perfected a form of enameling called cloisonné, where gold strips are soldered to a metal base plate making the outline of an image. The recessed spaces between the gold filigreed wire are then filled with a colored glass paste, or flux, that fills up the negative space in the design with whatever color chosen. Byzantine enamels usually depict a person of interest, often a member of the imperial family or a Christian icon. Enamels, because they are created from expensive materials such as gold, are often very small. Occasionally they are made into medallions that act as decorative jewelry or are set in ecclesiastical designs such as book covers, liturgical equipment like the chalice and paten, or in some examples, royal crowns. Collections of small enamels may be set together to make a larger, narrative display, such as in the Pala d'Oro altarpiece. Many of the examples of Byzantine enamel known today have been repurposed into a new setting, making dating particularly difficult where no inscriptions or identifiable persons are visible. The Latin Crusaders, who sacked Constantinople in 1204, took many examples of Byzantine enamel with them back West. The destruction of Constantinople meant that the production of enamel artwork went into downfall in the 13th century. It is possible that many examples left in the city were melted down and repurposed by the Ottoman Empire, who cared little about the religious significance of the art and could reuse the gold but not the glass.

The art of vitreous enameling is an ancient practice with origins that are hard to pinpoint. There are a few places that Byzantine craftsmen could have picked up the technique. Enameling is thought to have existed in an early form in ancient Egypt, where examples of gold ornaments containing glass paste separated by strips of gold have been found in tombs. However, there are questions about whether the Egyptians were using actual enameling techniques; it is possible that instead they were casting glass stones which were then enclosed, set into metal frames, and then sanded to a finish, similarly to how precious stones are set. In first century BCE Nubia, a method appears of soldering gold strips to a metal base, most often gold, and then filling in the sectioned off recesses with glass flux. This method, called cloisonné, later became the preferred style of enameling in the Byzantine Empire.

...
Wikipedia