BUFFING

Buffing is the finishing operation that gives metal surfaces their final shine, the highest degree of brilliance after Polishing. Where Polishing removes scratches and smooths the surface, Buffing “closes” it and gives it a Polished mirror finish by eliminating the last micro-scratches. It is carried out using brushes, discs, felts or soft leathers coated with a very fine buffing paste (rouge to To polish, alumina, micronized Diamond), dry or with a Lubricant. In watchmaking, Buffing is applied to the components of External parts (case, dial, hands) (Case, Bezel, Bracelet / Strap, Clasp) as well as to visible Movement parts (screw heads, bevels, polished steels). This is a demanding step, carried out by hand for high-end pieces, as excess pressure deforms the edges and “rounds off” the sharp angles sought after. When successful: buffing creates a deep, uniform, haze-free mirror effect, the signature of careful work. It is distinguished from Satin finish or brushing, which are matte or directional finishes.

Buffing is notably required to achieve the “black polish” (or mirror polish), an emblematic finish of fine watchmaking applied to the Steel parts of the Movement (Screws, springs, bridges). It is obtained by rubbing the part, previously made perfectly flat, on a tin or Zinc plate — the polishing block — coated with very fine Diamond paste. The surface thus obtained is so perfectly flat and reflective that it appears black under indirect Light, and shiny as a mirror under direct Light. This technique, inherited from 19th-century English watchmaking, requires an extremely steady hand: the slightest variation in pressure or contact produces dull areas or visible ripples.