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The Encyclopedia of Horology

Component record · Plates & finishing

Decorative Finishing

Verified

The collective term for ornamental surface treatments applied to movement plates, bridges and components — including Geneva stripes (côtes de Genève), perlage, black polishing, bevelling (anglage) and engine-turning (guilloché).

What it does

Serves an aesthetic and quality-signalling function, and in some cases (such as polished bevels reducing snag points, or perlage helping to disperse loose dust) has minor functional benefit alongside its decorative role.

How it works

Geneva stripes (côtes de Genève) are parallel decorative grooves cut into a plate or bridge surface with a rotating abrasive tool, historically also thought to help catch and disperse dust away from pivots.

Perlage is a pattern of overlapping circular scratches produced by a rotating abrasive tip, typically applied to base plates.

Bevelling (anglage) involves filing and polishing the edges of bridges and plates to a precise angle and mirror finish by hand in the finest work, a time-consuming technique strongly associated with haute horlogerie.

Black polishing brings a steel surface to a mirror-flat, near-black-appearing finish (depending on viewing angle) through fine abrasive polishing on a tin or zinc plate, used on small high-visibility parts such as levers and screw heads.

Evolution

From purely functional plate surfaces in early or utilitarian watchmaking to elaborate hand-applied decoration as a marker of quality and price tier, with mechanised approximations of these finishes appearing in industrial production and hand-applied versions remaining a hallmark of haute horlogerie.

Known variations

  • Geneva stripes (côtes de Genève)
  • Perlage (circular graining)
  • Bevelled and polished edges (anglage)
  • Black polishing
  • Engine-turned (guilloché) surfaces, especially on dials and cases

Identification for collectors

  • Hand-applied bevelling shows slightly irregular, individually finished angles under magnification, whereas machine-applied approximations tend to be more uniform
  • Presence and quality of finishing is a common (though not sole) indicator of a movement's price tier and manufacturer

Common failure modes

  • Finishing does not typically 'fail' functionally, but can be damaged or dulled by careless servicing, incorrect cleaning solvents, or re-plating that obscures original decoration

Related photographs

US Navy 061116-N-2959L-096 Lt. Cmdr. Christopher Mercer and Lt. Cmdr. Karen Sray converse with the Conning Officer about the ship's movement while standing watch on the bridge
US Navy 061116-N-2959L-096 Lt. Cmdr. Christopher Mercer and Lt. Cmdr. Karen Sray converse with the Conning Officer about the ship's movement while standing watch on the bridge — U.S. Navy photo by Mass Communication Specialist 3rd Class Dominique M.Lasco, Public domain. Wikimedia Commons file page

No confidently matched photograph of this subject has been found yet. These photographs show a closely related record, and are not examples of the type described on this page.

Sources & references

  1. Daniels, G., Watchmaking

Where sources disagree, the disagreement is stated rather than resolved silently.