The case features an unusual technique of enamel painting reminiscent of the German school, especially that of Augsburg. The disposition of the enamel scene, without the ring dividing the back from the band, which was typically present during the second half of the 17th century, is also unusual. It was a common practice in the eighteenth century to replace the movement in a particularly expensive or beautiful watch case, in order to take advantage of technological advances in horology. Examples can be found in numerous museums and private collections. A brief description of enameling Enamel is a form of glass. Its base is a colorless compound called flux, which is a combination of silica (obtained from fine white sand), lead, potassium or sodium salts, lime, and borax. By varying the proportions of these components, different degrees of hardness and resistance to the environment can be achieved. The metals most suitable for enameling are gold, copper, silver, and platinum, however other materials can be enameled, such as porcelain, majolica and lava stone. The higher the temperature, the more likely it is that the enamel will crack or that the counter-enamel will flake. The color effects are created by the addition of metal oxides, which give various hues. The Process A paste of extremely finely ground enamel powder mixed with distilled water or special oils is applied to one side of a metal plaque; counter-enamel is applied to the back. This equalizes stress during firing, making the enamel less likely to crack. When the water has evaporated, the piece is placed in the furnace and fired. Enameling of watch cases was usually practiced on gold and copper. The few surviving watches from the 16th century and the vast majority of those from the 17th century are almost always made of high-carat gold. The Techniques: There are several basic methods of decoration by enamel : 1. The technique called "filling", formerly called "proper enameling". In this technique, the earliest of them all, metal cells are formed and filled with a single color in each cell. This technique is of two basic types. In the first of these, "Champlevé", the metal is cut away to form a design which is then filled with enamel. A variation of this is the "Basse-taille" technique, in which the plate is first engraved or engine-turned and the resulting design is filled with enamel. In the "Cloisonné" technique, "walls" (cloisons in French) composed of small strips of metal are soldered to a plate, forming a design, and the cells are then filled with enamel. 2. Painting with enamels (enamel painting). In this technique, which originated in Limoges in the 15th century, different colors of enamel are applied, without any "walls". 3. "Grisalle". A technique in which monochrome, or "ca-maieu" effects are produced by applying white enamel over a dark ground. The gradations are achieved by varying the thickness of the layers. The "grisaille" technique originated in Limoges in the 15th century. 4. Painting on enamel. In this technique a uniform layer of enamel is fused onto the metal and then painted with pastes of different color oxides mixed with flux. The addition of flux is necessary to make the "paint" vitrifiable. This technique originated in Blois, being invented there by Jehan Toutin in the 1620?s. It is the most artistically demanding and the most suitable for decorating watch cases. Blois, as well as being the place of origin of this technique, was also the center of some of the fi-nest work. After the 1670?s, the rise of the Geneva school of enamel painting (as best represented by the Huaud family) with its high artistic quality and lower costs, led to the relative decline of the Blois school. For this reason, owners of fine old Blois watch cases often preferred to conserve their old cases, having more up to date movements fitted to them. 5. Plique-à-jour. In this technique, in which there is no metal backing, the enamel spans between metal frames, resembling a miniature stained glass panel. The earliest mention of this is found in Benvenuto Cellini?s "Treatises". It is the most fragile of all techniques and the early examples seem not to have survived. Antiquorum is proud to have presented, and to continue to pre-sent, some of the best examples of every type of enamel used to decorate watches and decorative objects.