Enamel

If Middle Byzantine clients and craftsmen showed in the case of steatite a willingness to adopt new materials, the history of Byzantine enamel suggests a similar openness to technical innovation. Before the late eighth or ninth century, enamels were produced by the method known since the Hellenistic period whereby molten glass was poured between boundaries of gold wire or strips of the same material soldered on their edges to the surface of an object. Much imitated by modern forgers, this technique is employed on an authentic pendant in the British Museum (Buckton 1994a: no. 98). But more celebrated pieces long supposed to be early Byzantine have been shown to be later medieval products. The cloisonne technique of enamels (in which the different colours of glass are separated by metal strips set on edge, cloisons) was a Western invention, unknown in the East before Iconoclasm. Thus the box at Poitiers made to house a fragment of the True Cross sent by Justinian II to Queen Radegundus in 569 (Buckton 1988; Durand 1992: no. 241; Cormack 1994: 68-9) cannot be contemporary with the gift of the relic but was probably a work of the eleventh century. By this time, the Vollschmelz technique, so called because the enamel completely covers the underlying metallic ground, had been perfected.

This Vollschmelz technique is seen at an early stage of development in the crown of Leo VI, now in the treasury of San Marco in Venice. In the course of the tenth century another method of production, known to scholars as Senkschmelz, was also in vogue. In this technique, the melted glass is let into the cavities in the metal ground leaving much of this substrate exposed, as on the cross reliquary at Limburg-an-der-Lahn which bears an inscription of Basil, a son of Romanos II, identifying him as proedroSy a title he received in 963 or 964. While the aesthetic effect of objects like Leo VTs crown is due primarily to its jewel-like enamels, most strikingly a deep translucent green, the impact of the Limburg reliquary, in which precious stones are also set as if to rival the effect of the enamelled cells, is a function of the exposed gold ground. This effect is seen most dramatically in the so-called Goldene Tafel at Schloss Nymphenburg (Kahsnitz, in Baumstark 1998: no. 30). The Nymphenburg plaque consists of a single sheet of gold measuring 24.3 x 17.5 x 0.1 cm, weighing in all 430 g. This prodigious expenditure of precious metal is clearly intended to convey the maximum value to be attached to the image of the Crucifixion on it. Perhaps inevitably such ostentatious expenditure led to a reaction and greater economy of materials: silver-gilt and copper substrates were tried, particularly when in the twelfth and thirteenth centuries Vollschmelz that concealed the underlying metal (and was employed perhaps for that purpose) came back into fashion. But gold, which does not oxidize and of all metals has a coefficient of expansion closest to that of glass, served, beyond its obvious symbolic significance, as the optimum setting for enamel and remained the substrate of choice until the end of the empire.

Enamelling demonstrates what was possibly the most inventive and ingenious of all Byzantine crafts. Its practitioners simultaneously used a variety of techniques. On the lower part of the Holy Crown of Hungary, for instance, inscriptions and figurative plaques were created by different means, and even the plaques themselves display diverse methods of preparation (Kovacs and Lovag 1980). All in all, this variety reflects the passion in Byzantium for polychrome brilliance, which the medium of enamel perfectly served. As the very emblem of lavishness, enamel work constituted a perfect medium for gifts, like the Hungarian crown, and a prime stimulus to overseas demand, famously expressed in Doge Ordelafo Falier s order for the Pala d’Oro as an antependium to the main altar of San Marco. This particular commission was placed in Constantinople, but there is no reason to suppose that the craft of enamelling was entirely confined to the capital. Theoretically, wherever glass was made and gold or copper mined (as in eastern Anatolia), enamel could be produced. Although attributions of individual pieces to Thessalonike, southern Italy, Kievan Rus, Georgia, and the Christian communities of the Christian East may be no more than educated guesses, the widespread distribution, particularly of secular jewellery (ear - and finger-rings, enkolpiuy and other adornments), can hardly be always explained as the result of long-distance trade.