Champlevé literally means «raised field»: it is not the color that rises, but the metal that remains around the cavities. I carve the base — gold, silver, copper — and leave the walls in relief to frame each zone of color. It is the opposite of what it appears at first glance.
The process begins with engraving, which can be executed with a burin, a burr, or acid. The depth of the cavities is not arbitrary: too shallow an excavation does not retain the enamel during firing, too deep makes final leveling impossible. From my workbench I often see dials where this calibration is approximate — the enamel overflows or remains sunken, and the finished surface is never flat. The precision of the engraving determines the quality of the result before fire even comes into play.
The vitreous enamel is deposited into the cells in powder or paste form, then the piece goes into the oven. Here enters the distinction with Grand Feu: Grand Feu describes the high-temperature firing method, around 800 °C; champlevé describes the structure of the receiving surface. The two terms are not alternatives — they are often used together, because champlevé cells are fired Grand Feu. A dial can be Grand Feu without being champlevé, if the enamel is applied to a flat surface; but a properly executed champlevé is almost always fired at high temperature.
The number of firing passes varies. Some craftsmen apply enamel in successive layers, firing each layer, to obtain color depth or translucent effects — documented cases reach nine layers. Each firing is an irreversible risk: temperatures are never identical, and thermal stresses can crack both the enamel and the underlying metal.
The difference with cloisonné is structural: in cloisonné the walls separating colors are thin metal strips soldered to the surface, not obtained by engraving. In champlevé the supporting structure and the decorative structure are a single piece of metal. This continuity makes champlevé more mechanically robust, but also more demanding in the engraving phase.
The technique applies to dials as much as to bezels and cases. On convex surfaces — the spherical center of certain astronomical dials, for example — difficulty increases because the enamel tends to flow during firing. Any deviation from the horizontal plane requires adjustments in paste viscosity and kiln time.
