Sandblasted finish

Sandblasted finishing is one of the few surface treatments in watchmaking that doesn't depend on a sharp tool, but rather on the pressure and granulometry of projected particles. The principle is straightforward: I fire microscopic abrasive particles — quartz, corundum, or glass beads depending on the desired result — against the surface of metal or ceramic, breaking the polished plane and creating a uniform texture that diffuses light rather than reflects it.

From the workbench, the most useful distinction is between sandblasted and microblasted. In classical sandblasting the particles are coarser: the result is matte, tactilely perceptible, almost granular. In microblasting the particles are extremely fine and the resulting surface is silkier, almost velvety to the touch, with a more refined and homogeneous matte finish. Both eliminate reflections, which is essential on watches designed for tactical or military use — the parkerizing of American military components, referenced by specification GG-W-113, was essentially the same concept applied through chemical means. When mechanical sandblasting spread to civilian watches in the twentieth century, the sober aesthetics it produced ceased to be an exclusively military characteristic.

Sandblasted finishing almost always exists in contrast with a polished area. A case that is entirely sandblasted would be monotonous; it's the alternation with polished edges or mirror-finished bevels that gives dimensionality to the piece. This interplay is evident on cases in grade 5 titanium, where the material's hardness makes sandblasting relatively stable over time, but also on ceramic — a naturally hard and difficult-to-work material — where manufacturers combine satin-brushed, sandblasted, and mirror-beveled surfaces on the same component.

On dials, sandblasting serves a different function: it reduces reflections that would make reading difficult, and can be used as a background for degradé effects or as a contrast against a satin outer ring. In some cases the sandblasted dial then receives a rhodium plating, which adds a silvered veil without restoring polish.

On movements, sandblasted bridges — called sandblasted bridges or black bridges when darkened — are found paired with other artisanal finishes such as manual edge beveling. In that context sandblasting is not a shortcut: it's the finish deliberately chosen to eliminate any reflection that would distract from the mechanism's geometry.