Of the many decorative arts, enamelling is one of the most beautiful, having a singular charm of limpid or opalescent colour of great purity, richness and durability, and being capable of a most refined and varied treatment for the enrichment of metals.

Enamel is a vitreous or glass compound, translucent, semi-translucent or opaque, owing its colouring properties to mineral oxides, or sulphides, a fine opaque white being produced by oxide of tin. These enamels require different degrees of heat in order to fuse them and to cause their adhesion to the metal. Enamels are divided into three classes, CloisonnÉ, ChamplevÉ and Painted Enamels.

CloisonnÉ enamel is that in which the cloisons or cells are formed by soldering thin, flat wire of metal upon a plate of copper, the cloisons, being filled with the various enamels, in powder or in paste, then, in order to vitrify the enamel, exposed to heat in a kiln, if upon a flat surface, or by the aid of a blow-pipe if upon a curved surface.

CloisonnÉ was in use from the early dynasties in Egypt, many fine large pectorals having been found in the tombs. These usually have the form of a hawk and are of gold or bronze with well-defined cloisons, which were filled with carefully fitted coloured paste or glass, and this undoubtedly was the origin of the true or vitreous cloisonnÉ enamel. Byzantine enamel is invariably cloisonnÉ and one of the most beautiful examples of this period is the Pala d’Oro of St. Mark’s at Venice, A.D. 976. Perhaps the Chinese and Japanese have carried this cloisonnÉ to its greatest perfection in softness of colour and beauty of technic. The earliest Chinese cloisonnÉ is of the Ming dynasty, 1368-1643; this has heavy cast metal grounds with low toned colours and deep reds and blues. Under the Thsing dynasty, which commenced in 1643, the colours became brighter and the designs more refined.

Early Japanese cloisonnÉ or “Shippo” was doubtless derived from Chinese or Persian sources, and it is characterised by extremely thin beaten copper grounds and the frequent use of a dark green ground in place of the dark blue of the Chinese cloisonnÉ.

The Japanese cloisonnÉ reached its culmination during the last century, when many splendid examples of refined and delicate enamels were produced, remarkable for their beautiful opalescent and translucent colour. Gold cloisons with opaque and translucent enamels were frequently inserted in iron or silver objects by the Japanese of this period.

An early example of English cloisonnÉ is the jewel of King Alfred, now in the Ashmolean Museum, Oxford: this has a rich setting of opaque and translucent enamels. A fine Celtic cloisonnÉ treatment may be seen in the Ardage chalice, where the cloisons were cut out of a plate of silver and embedded in the enamel while soft. These Celtic craftsmen also had a beautiful treatment of enamelling by engraving or pressing a pattern in intaglio, or sunk relief, on an enamelled ground, and then filling these intaglios with other enamels.

A most exquisite kind of enamel called “Plique À Jour,” was used by the Byzantines; this was composed of open filigree cloisons, filled with translucent enamels.

ChamplevÉ enamel is formed by engraving, casting or scooping out the cloisons from a metal plate, leaving a thin wall or boundary between each cloison, which is then filled with the various enamels as in the cloisonnÉ method. This ChamplevÉ method was practised in Britain before the Roman conquest, and was probably derived from the Phoenicians, who, centuries before the Romans came to England, had traded with Cornwall for tin. The beauty of colour and perfect adaptability of these early enamelled brooches, fibulÆ and trappings of horses of the early Britons and Celts, are remarkable, showing a fine sense of colour and a harmony of line and mass. A splendid bronze Celtic shield (fig. 4, plate 13), now in the British Museum, is enriched with fine red bosses of enamel. These ChamplevÉ enamels upon bronze have usually an opalescent or cloudy appearance caused by the fusion of the tin in the bronze alloy during firing. ChamplevÉ enamels were used with rare skill and refinement to enhance the beautiful art of the goldsmith during the Middle Ages; the Chalice, the Paten, the Reliquary, the Thurible, the Crozier, and the bookcovers of the Churches, especially, were enriched with beautiful enamels. Classed among the ChamplevÉ enamels is that method called Jeweller’s Enamel or “Baisse Taille,” in which the plate is engraved in low relief or beaten up in repoussÉ and then flooded with translucent enamel. The Lynn cup of the time of Richard II. is one of the oldest pieces of corporation plate and is covered with fine translucent blue and green enamels.

In India, where fine colour is a splendid tradition, ChamplevÉ enamel soon attained a remarkable perfection of technic and purity and brilliance of colour almost unknown to the Western nations. The ChamplevÉ enamels of Jaipur have most beautiful lustrous and transparent blues, greens and reds laid on a pure gold ground. Pertubghur is renowned for the fine green or turquoise enamel fired upon a plate of gold; while the enamel was still soft a plate of pierced gold was pressed into the enamel. This pierced plate was afterwards engraved with incidents of history or hunting. In Ratain, in Central India, a similar enamel is made having a fine blue in place of the Pertubghur green.

The fine monumental brasses, of which many still remain in our English cathedrals and churches, are a survival of the ChamplevÉ process, the cloisons, being usually filled with a black Niello, but occasionally the heraldic shields are enriched with coloured enamels. During the 11th and 12th centuries, Limoges was renowned for its fine ChamplevÉ enamels, but early in the 15th century Painted Enamels were introduced and Limoges became the centre of this art, called late Limoges or Grisaille Enamel. Image unavailable. The enamel colours were now used as a pigment, and were painted and fired upon a copper plate. The enrichments in grisaille, or grey and white, were used upon a black, violet or dark blue ground, the grisaille afterwards being enriched with details of fine gold lines. These Limoges enamels have a splendid technic, but they lack the charms of the luminous colour and judicious use of enamels of the early ChamplevÉ period. The most renowned masters of the painted enamels of Limoges were Penicand, 1503, Courtois, 1510, Pierre Raymond, 1530-1570, and Leonard Limousin, 1532-1574. About 1600-1650, Jean Toutin and his pupil Petitot produced some fine painted miniatures in opaque enamels upon gold, remarkable for delicacy and perfection of enamelling. In 1750, painted enamel was introduced into England and produced for about 30 years at Battersea by Janssen. The enrichment consisted of flowers painted in natural colours on a white ground. A similar enamel was also produced at Bilston in Staffordshire.

The finest enamels undoubtedly are those in which the enamel is used in small quantities, such as in the Celtic jewellery, the bookcovers, and the Church and Corporation plate of the Gothic and early Renascence period, and the early Byzantine cloisonnÉ, such as the Hamilton brooch in the British Museum, and the Pala d’Oro of St. Mark’s, Venice, which was made at Constantinople for the Doge Orseolo in 976 A.D., and has 83 panels of fine cloisonnÉ enamel set in a framework of gold.

The “Plique À jour,” the “Baisse taille” and the Pertubghur enamels are fine examples of appropriateness of treatment with translucency or opalescence and richness of colour.

The Japanese cloisonnÉ with its literal treatment of natural forms, and the painted enamel portraits of Francis I. and contemporary princes by Leonard Limousin, clever as they undoubtedly are, lack the depth and purity of colour obtained by the early methods. Frequently, however, the Penicauds, Nardou, and Jean I. and II. obtained some richness in the painted enamels by the use of “Paillons” or pieces of metallic foil which were afterwards flooded with translucent enamel.