What Is Cloisonné Enamel?

Cloisonné enamel is a metalworking technique in which thin strips of gold, silver, or copper are soldered to a metal base to form small cells (cloisons in French) that are then filled with colored, powdered glass paste and fired in a kiln. The heat fuses the glass to the metal, producing a brilliant, durable, and intensely colored surface. The technique was developed in the ancient Mediterranean and Near East, reached its early medieval high point in the workshops of Constantinople, and was later adopted by the Carolingian, Ottonian, Mosan, and Romanesque metalworkers of the Latin West. For the broader context of early medieval metalwork, see the Carolingian and Ottonian art and early medieval art and architecture, and for the related discussion of the Byzantine tradition, see early Christian and Byzantine art. The famous Insular metalwork is treated in the Insular and Anglo-Saxon art, and the related question of the Treasury of Saint Mark’s is treated in the linked long-tail.

Cloisonné enamel was one of the most prestigious art forms of the early medieval world. The technique produced objects of extraordinary brilliance, durability, and visual richness, and the resulting works were used in the liturgy, given as diplomatic gifts, and worn as jewelry by the imperial and ecclesiastical aristocracy. The great cloisonné enamels of the early Middle Ages — the Pala d’Oro of St. Mark’s, the Lothar Cross, the Limburg Staurotheke, the Sutton Hoo purse lid, and many others — are among the most famous surviving works of early medieval art.

The Technique

The technique of cloisonné enamel involves several distinct steps. The artist first prepares the metal base, typically of gold, silver, or copper, by hammering it into a thin sheet and cleaning the surface. The artist then bends thin strips of metal — typically gold or silver — into the desired shapes and solders them to the base to form the cells. The cells may be of any size and shape: small and round, long and narrow, irregular and free-form. The artist then fills the cells with powdered glass paste of various colors and fires the whole in a kiln. The heat fuses the glass to the metal and to the cells, and the result is a brilliant, durable, colored surface.

The technique requires considerable skill. The metal strips must be bent to the precise shape, soldered to the base without burning the metal or the base, and arranged in a visually coherent pattern. The glass paste must be ground to the correct fineness, mixed in the correct proportions, and applied to the cells in the right amount. The firing temperature and duration must be carefully controlled, and the piece must be allowed to cool slowly to avoid cracking. The technique was a closely guarded craft, and the workshops that produced cloisonné enamel were highly specialized and well patronized.

The Materials and Pigments

The materials of the cloisonné enameler were gold, silver, or copper for the base and the cells, and colored glass paste for the fill. The most expensive material was the gold base, used for the most prestigious objects, and the most common was the copper base, used for less expensive works. The most prestigious glass was the red glass made with cuprous oxide, which produced the brilliant red that was a signature of the Byzantine and Carolingian cloisonné. The other colors included blue (made with cobalt oxide), green (made with copper oxide), yellow (made with lead and antimony), white (made with tin oxide), and black (made with manganese dioxide). The pigments were a small but extremely well-chosen palette, and the resulting colors were brilliant, saturated, and remarkably durable.

The Major Examples

The major surviving examples of early medieval cloisonné enamel include objects from the Byzantine, Carolingian, Ottonian, Insular, and Romanesque periods. The most famous Byzantine examples include the Vienna Dioscurides (c. 512, with later additions), the Limburg Staurotheke (c. 950), the Staurotheke of Fiesole (c. 800), the Pala d’Oro of St. Mark’s in Venice (begun in Constantinople, completed in the Latin West), and the many other liturgical objects produced in the imperial and monastic workshops of Constantinople. The most famous Carolingian and Ottonian examples include the Lothar Cross (c. 1000, made for the Ottonian emperor Otto I or his successors), the Cross of Mathilde (c. 1000), the Bernward Cross (c. 1000), and the great reliquaries and book covers produced in the imperial and ecclesiastical workshops of Essen, Cologne, Hildesheim, and Reichenau. The most famous Insular example is the great Sutton Hoo purse lid, with its cloisonné garnet and millefiori inlay.

The Decorative Programs

The decorative programs of the cloisonné enamels were drawn from the Christian iconographic tradition, the imperial iconography of the Byzantine and Carolingian courts, and the ornamental vocabulary of the early medieval metalworking tradition. The most common subjects included the Virgin and Child, the Crucifixion, the Christ in Majesty, the evangelist symbols, the saints, the angels, the imperial portraits, and the ornamental motifs of interlace, spirals, key patterns, and zoomorphic forms. The combination of figural and ornamental imagery, of gold or silver cells and colored glass, of Christian and imperial symbolism, is the most distinctive feature of the early medieval cloisonné enamel.

The great cloisonné enamels of the early Middle Ages were the most prestigious objects the early medieval culture could produce. The Pala d’Oro of St. Mark’s in Venice, the Lothar Cross in Aachen, the Limburg Staurotheke in Limburg an der Lahn, the great Sutton Hoo purse lid in the British Museum, the Berthold Cross in the Metropolitan Museum, and the Vienna Dioscurides in the Österreichische Nationalbibliothek are among the most famous surviving examples. The technique continued in use in the Byzantine, Romanesque, Gothic, and later medieval metalworking traditions, and it remains one of the most distinctive and most important techniques of the decorative arts of the Middle Ages.