Everything You Need To Know About Watch Finishing Techniques

Nine times out of 10, when you talk about fine finishing in the context of high-end watchmaking, you're talking about what's going on inside the case. From the fairly common straight lines of Côtes de Genève (or any other regional variant of the same technique) through to more dramatic techniques like anglage or black polishing, the caliber of a watch is a microscopic wonderland, a mechanism polished to within an inch of its proverbial life. Of course, brushing and polishing exist on watch dials and cases too, and the larger surface areas and less complex components allow watchmakers to really go to town, creatively speaking. There's a whole suite of complex and beguiling techniques and crafts that can turn any watch into a work of art.

Typically these sorts of crafts are collectively referred to as Métiers d'Art — decorative handcrafts practiced by a handful of specialized craftspeople. From miniature painters to master engravers, these artisans can create wonderful scenes and effects in an area a few millimeters across. Indeed, the popularity of this sort of watch finishing has led not just to a renaissance in these skills, but in some cases; it's saved them from being forgotten forever. Here are just four examples of these fantastic finishes.

Enamel

Capable of being both visually arresting and surprisingly subtle, enameling on watches is a technique with a long history of being used as far back as the 17th century. Essentially, enamel involves silica powder mixed with other compounds to give the enamel color, which is then applied to the surface, either as a powder or suspended in water. The enamel is then fired at a heat of more than 800 degrees Celsius, cooled and sanded. This heat is where the common name 'Grand Feu', or great heat, comes from. This labor-intensive process is repeated many times to achieve the final look. The reward is worth the effort, as enamel is exceptionally hard-wearing (though brittle), and the color will never fade over time. This is the base level of what enamel looks like in watchmaking; there's a range of Métiers d'art techniques that elevate this process even further.

Champlevé sees enamel poured into the hollowed-out areas of metal, typically to accentuate or highlight the decorative design. Cloisonné works off a similar theory, except here the artisan creates a delicate raised frame — often from minute gold wires — to form the borders around the different areas of enamel. This technique is perhaps the most well-known, often found on Patek Philippe and Rolex watches — indeed, one of the most remarkable (yet least remarked upon) aspects of the Rolex 'Puzzle' Day-Date is the vivid cloisonné dial. Flinquê is a technique where translucent enamel is applied over a guilloché base and has been used to great effect by Kari Voutilainen. All these techniques blur the lines between art and craft, but the rarefied world of miniature enamel painting takes it to another level. Painting at any scale is a challenge, but creating a scene mere millimeters wide in fickle enamel is a task few attempt. The best-known example of this nearly forgotten art is Anita Porchet, an in-demand artisan whose finely painted enamel dials grace the watches of Patek Philippe, Vacheron Constantin, Hermès and more. 

Engine Turning or Guillochage

Enamelling is, at its heart, an additive process; engine turning — more often called guilloché — is a process of mechanical engraving using either a rose engine or straight-line machines to create complicated geometric patterns. A rose engine machine is a type of lathe, which, thanks to a pre-programmed wheel called a rosette, allows for precise and consistent pattern creation. A straight-line engine follows a similar formula but in a linear cut. Guilloché isn't unique to watchmaking, but the finishing technique was popularized by Abraham Louis Breguet and is still a hallmark of the Breguet brand today. 

Guilloché is most commonly seen in a range of established patterns, from the famous Clous de Paris and Tapisserie styles, to radial sunburst and the pleasing barleycorn pattern. Most watch brands stick to the established codes of Guilloché, but one upstart independent, J.N. Shapiro has made a name for himself by developing his own patterns — like his trademark 'infinity' weave. In fact, his latest watch, the proudly American-made Resurgence, features guilloché on the dial, case and calibre — shining a light on the fine art of engine turning. 

Engraving

Most people's experience with engraving and watches extends to a sentimental date on the inscription on a caseback — but this is the bare minimum that a talented engraver can achieve with a watch and a burin. Technically, engraving is a broad term that encompasses any cutting of metal, such as the guillochage discussed above. Here though, we refer to it in the sense of hand-engraving, where a skilled and steady hand makes precise incisions into the metal with a razor-sharp burin, often guided by a microscope. It's a nerve-wracking skill and one with no margin for error. But the results speak for themselves. 

Some of the more spectacular engraved watches that have been released recently are Vacheron's Constantin's Tribute to Great Civilisations pieces, made in collaboration with the Louvre; these watches use an array of artisanal crafts above and beyond engraving to recreate iconic historical artifacts. These pieces showcase the incredible visual impact you can achieve by stacking technique on technique, to create a world within a watch.

Gem-Setting

Finally, when we think of gem-setting, we typically think about diamond-set hour makers or a rainbow bezel. It's easy to truly reduce a gem-set watch to the number and weight of stones. Honestly, though, that's a disservice to what goes into top-tier stone-setting. A process that starts well before the diamonds meet the case. Once the watchmaker knows what they want to achieve with stones, they need to be sourced, graded and cut. This process is much more involved than it may seem, as top-quality stones aren't the easiest to source. Take Rolex, for example. The brand makes a lot of gem-set watches, and every single one is sorted by hand, with special care taken to achieve consistency in color and hue. Cut must also be taken into account, as the style and quality of cut will impact on how the stone amplifies light and reflection. 

Sticking with the example of Rolex, their rainbow bezel is more than just an object of cult cool. It's an example of an excellent technical gem setting. The precision of the color gradient, achieved with naturally colored stones, is fantastic, as is the precision of the cut and placement. You cannot see the gaps between the stones, and the lines and surfaces are in perfect harmony. Compare it to an aftermarket gem-set watch, and the quality is leagues apart. Naturally, brands like Chopard, Cartier and Piaget, all with strong jewelry pedigree, excel in this area, with developments like Cartier's vibrating setting taking gem-setting to the next level.

The beating heart of the watch will always be the movement, but for the rarefied world of Métiers d'Art, the soul will be the face it shows to the world.