LACQUER

In watchmaking, lacquer refers to a varnish, of chemical or natural origin, generally translucent or transparent, applied for both aesthetic and protective purposes. On a Dial, it brightens or colours the surface, adds optical depth and protects the underlying decoration — Guilloché (engine-turning), Engraving, Enamelling partial — from oxidation and scratches. It is also used as a temporary Protective coating to isolate an area during a Surface treatments operation, or as a background tint on an engraving, whose motif it brings out by contrast. The lacquers used can be colourless, coloured throughout their Mass, or loaded with pigments, metallic flakes or Mother of pearl. Their application requires rigorous cleanliness, precise dosing and mastery of drying, as the slightest dust, drip or air bubble is immediately noticeable on a finished dial. Among the most demanding techniques is urushi lacquer, a natural resin extracted from the sap of the lacquer tree (Toxicodendron vernicifluum), applied in successive coats dried in a humid atmosphere and used by certain manufactures for dials or maki-e motifs.