This kind of enamel is done on a smooth plaque of thin copper or other metal which has been slightly domed for the purpose. It is covered with a coat of enamel which forms the ground, the back also being enamelled in order to equalize the contractile strains, and fired. The design is then painted in white of suitable thicknesses, which on being fired form tones with the ground colour according to their relative opacity, and the result is called grisaille. This is a very charming form of decoration in itself, and is frequently done with that intention. Usually, however, coloured enamel is painted over it, the work being carefully fired at each stage, a very anxious process, and finally it may be heightened with gold after the manner of the illuminations. An additional method of obtaining decorative effects, in diapers, etc., presents itself in the power of scratching the painted gold with a needle before firing. Fig. 176, executed in this manner, is a plaque that is the property of W. H. Weldon, Esq.
From the capacity of painted enamel to imitate the effects of the illuminations it presents few technical difficulties as design. Its practice, however, is another matter, as may be imagined when the risk of the numerous firings is taken into account.
A form of enamel that is occasionally used for badges and similar heraldic subjects is that which is called bassetaille. In this method the subject, usually in the form of a medallion, is carved in low relief and the transparent enamel fluxed completely over it, the surface being afterwards ground and polished. The varying thickness of the enamel, from the deepest part of the relief to the highest, gives a quality of gradated colour that is extremely beautiful. In a badge or jewel of this kind there is, of course, a rim raised to the height necessary to contain the enamel and extending above the highest point of the carved subject.
Fig. 176.—Enamelled Plaque. Crest of W. H. Weldon, Esq., C.V.O., Norroy King of Arms. Geo. W. Eve.
Still another method is that which came into use in the fifteenth century for jewels, and is known as plique-a-jour, a kind of transparent Cloisonné which is said to have been produced by Cellini, who certainly knew of it. It is an extremely difficult process, but the effect is remarkably precious and jewel-like, the enamel being fired into a design which has been built up of bent wire and soldered together like Cloisonné without the bedplate, so that the work looks like a miniature piece of stained glass (as indeed it is) and of great beauty. In a similar way a design may be cut out or saw pierced through a plate of metal and filled with enamel à jour.
In all methods of enamelling, a drawing of the design must of necessity be first made, and it is of course essential that the designer should have a practical knowledge of the methods that are concerned, the design and the finished work being necessarily interdependent, and though written descriptions are useful to indicate the nature of the processes nothing can supply the place of actual experiment under competent instruction. Familiarity with the practical side of art craftsmanship need not imply an intention to produce the work itself, but is absolutely necessary to adequately designing for it.
Enamel is increasingly employed in commemorative tablets and in objects of ceremonial use, and is also used with equally charming effect on the decoration of cabinets, jewel caskets, and other boxes to which as wedding gifts or other presentations, heraldry, properly marshalled and well executed, is peculiarly appropriate. To such purposes the “Limoges” painted method readily lends itself, especially when the general design is of somewhat ornate character. With regard to the mounting of enamels, metal as framework seems especially suitable to their perfect display, as the setting to the gem, and so when a plaque is used to decorate a wooden panel it is well to introduce metal as an intermediary. But, nevertheless, I have found a well-cut ebony frame very satisfactory in itself, and the matter is clearly one for experiment.
Champlevé and Cloisonné go well with the more severe styles of design, both ornamental and heraldic, in fact, enamel goes best with styles similar to those with which it was associated in the early practice. The one with the freedom of the Renaissance, the others with the greater severity and strength of the Gothic.
For salvers, inkstands, lamps and other utensils heraldry in Champlevé enamel is very suitable and it is somewhat remarkable that it is not more often employed in place of the engraving which is usually inappropriate because of its lack of decorative quality.