Table of Contents
Gestures that sculpt light
Even before reading the hours, the eye enjoys traveling. On a pearl plate, the light clings like fine sand. On a deck streaked with Côtes de Genève, it glides in satin ribbons. These iconic watchmaking decorations are not an artifice: they speak of know-how, filter dust, guide the eye and sign a style. How are they born, concretely, in the workshop? Immerse yourself in the intimacy of the benches where diamond stone and watchmaker’s wood tame the metal.
Perlage: the grainy secret of turntables
Perlage — also called circular graining — lines the plates and hidden areas. Far from the spotlight, he nevertheless plays an essential music: that of a regular grain, obtained by the repeated imprint of a small abrasive tool. We lower a pawn onto the surface, we raise it, we shift with a constant step, and we start again, until we cover the metal with a scattering of circles which overlap by a third to a half. Seen up close, it is a fish scale; from a distance, a velvet.
Tools and material
- A precision drill press or beading machine with micrometric descent.
- Points made of wood (boxwood, pegwood) or rubber, loaded with diamond-type abrasive paste.
- A crossed plate (X/Y) for regular steps and constant overlaps.
- Varied tip diameters to approach edges and openings.
The choreography is slow and measured. We often start at the edge of an open area, to “lose” the last prints under a bridge or a barrel. The circles must remain clear, neither too deep (which will weaken the piece), nor too superficial (which will fade). Good beading breathes: same density, same cadence, and a graduation of diameters to lick the contours without overflowing.
Côtes de Genève: the parallel caress of the bridges
The Côtes de Genève, or “Geneva stripes”, are these wide satin ribbons that cross the bridges. They are neither engraved nor printed: they are controlled micro-scratches, traced in perfectly parallel bands. Historically Genevan, they come in straight (classic), circular (on the rotors) or radiating ribs. In Germany, in Glashütte, their cousins often adopt a broader and more pronounced rhythm.
The gesture and the machine
- A dimensioning (coasting) machine: a cylindrical tool or an abrasive strip moves over the part while the operator ensures regular advance.
- A fine abrasive (emery, diamond) on wood, felt or canvas, for a smooth and controlled cut.
- A pitch template to guarantee constant strip spacing.
We first prepare the surface with a light satin finish, then we trace the first strip by guiding the longitudinal advance. Each pass overlaps very slightly, creating a silky fade without “steps”. On a complex bridge, virtuosity consists of running the coast beyond a break, then resuming it on the other side as if nothing had happened. The beveled edge must remain clear: no rib must “bite” the bevel.
More than decoration: functions and culture
We often forget it, but these decorations have a use. The beading, through its micro-topography, traps residual dust far from the pivots. The Côtes de Genève break the reflections and guide the eye, clarifying the reading of the architecture. Above all, they are a cultural language: in Geneva, they meet the historical requirements of the Hallmark; in the Vallée de Joux, they are combined with mirror beveling; in Glashütte, they are large and contrasting, sometimes on a three-quarter bridge.
The sequence in the workshop
- Preparation: leveling, deburring, light satin finishing to standardize the surface.
- Beading: first the central areas, then approaching the edges with finer points.
- Côtes de Genève: strip tracing, pitch control, invisible restarts after unhooking.
- Beveling and mirror polishing: bevels, internal angles and black polished screw heads, for edges that cut off the light.
- Final cleaning: degreasing and inspection under a magnifying glass to track down the slightest overflow.
Depending on the house, beveling and ribbing can alternate, but the golden rule remains the same: preserve impeccable edges and clean transitions. The slightest false gesture leaves a trace that nothing can erase.
Signatures, variants and anecdotes
At Patek Philippe or Vacheron Constantin, the ribs are obvious, with a particularly silky fade. Audemars Piguet takes care of the openwork bridges where the regularity of the bands becomes a balancing act. In Glashütte, A. Lange & Söhne favors sharper ribs and beveling of almost metallic purity. On the rotors, the circular ribs depict a moving sun, while the snailing – another decoration, in tight spirals – appears on the barrel wheels and pawls.
If the industry has automated some of the passes, the hand remains sovereign to catch a connection, feel the pressure, dose the abrasive. We recognize the school at first glance: a too wide step, a sharp fade, an irregular overlap betray a hasty hand. Conversely, beading at the right cadence or ribs that “breathe” between two screws speak of patient hours at the bench.
What the eye tracks: quality criteria
- Regularity: constant pitch, homogeneous patterns, identical depths.
- Clean edges: no rib crosses a bevel; no beading bleeds onto a chamfer.
- Invisible connections: perfect continuity after an unhook or multiple bridge.
- Cleanliness: no stray scratches, no “floating” waves or crushing.
- Harmony: coherent dialogue between beading, ribbing, beveling and mirror polishing.
Maintenance and collection: the ethics of respect
These decorations are a skin. Aggressive polishing could erase them, and wild refinishing could distort a period bridge. In the collection, we favor reversible interventions and respect for the original grain. Beading or ribbing that is too “new” on an old watch raises questions: the seasoned eye prefers an honest patina to an approximate re-creation. In service, the best manufacturers redo the patterns with in-house templates, to preserve the visual DNA of the caliber.
As a conclusion
Perlage and Côtes de Genève do not seek cold perfection, but accuracy: that of a regular gesture, a controlled time, a sure taste. They don’t just say “beautiful”, they say “well done”. And when we turn a watch over and the movement lights up, we think less about the technique than about the breath that drives it: a few grains, a few ribbons, and watchmaking begins to tell a story.
