After the mechanical movement, with its constellation of tiny cogs and levers, dial-making is the hardest horological craft to master. Even the simplest dials involve dozens of processes, while the finest examples draw on hand crafts that have nearly died out. A few years ago, I remember speaking to Vacheron Constantin’s then-CEO, Mr Juan Carlos Torres. “I have seen so many crafts disappear during the past 30 years,” he lamented. “Engine-turned engraving almost disappeared, enamelling as well. At one point, there were only two or three decent enamellers left in the world.” The situation has improved little since: next time you look at your watch, consider that it’s not just the movement beneath that relies on a rare set of skills to create.

A watch’s dial begins life with wafer-thin brass discs, textured beneath 200 tons of pressure. Then 2mm-long brass pins acting as “feet” are electrically welded to the back, before lateral or radial patterns are made with rotating copper brushes. Then they’re either spray-painted (up to 15 layers, each individually oven-dried) or electroplated in baths of black nickel, copper, silver, gold or rhodium. And that’s before you’ve hand-applied the numeral batons or separately fabricated sub-dials.

If you think that sounds complicated, it’s just the beginning. Over the years, watch dials have always served as a canvas for artistic decoration as well as an expression of the intricacy and precision that lie beneath them. Here are five of the most celebrated crafts in the industry, from painstaking works of art to geometric, abstract finishes.

From the 18th century, the dials of classical pocket watches were invariably coated with bright white enamel, readable by the dimmest candlelight. From this, the cult of miniature painting evolved, which reached a pinnacle in France in the 18th and 19th centuries, when entire watchcases and even their inner surfaces were covered with exquisite miniatures.

Enamel is still used as a base surface (see below), but a more cost-effective route is organic lacquer (originally derived naturally from the sap of the lacquer tree), the successive transparent layers of which are cured at room temperature. It has three other advantages over enamel – a perfect surface consistency, a perfectly even shade of white and shock resistance. The painting is the preserve of a small number of artisans, who can take up to 10 days to complete a single dial, working with ultra-fine brushes. Typically, the enamel is fired after each colour is applied.

Three-dimensional numerals, indexes, sub-dials and logos are generally “applied” to a decent watch dial, that is, pinned in as separate components. The alternative is for watchmakers to lay themselves as bare as can be by ink printing on top of the lacquer or enamel. You’d think ink would present the easier route, but think again.

Enamel dye is smeared onto a steel cliché that is photolithographically engraved with the design of the dial’s indices and marks. The ink is picked up from the cliché by a smooth, torpedo-shaped gelatine pad, which is then blotted onto the flawless enamel dial. Despite the seemingly random “squash”, the impression it leaves is astonishingly crisp.

The dial is then fired again, to fuse this new layer of enamel, then flattened using a piece of carbon. This operation requires great skill and accounts for a large portion of waste as the carbon may leave marks.

Enamel is produced by coating a brass dial with a low-melting-point white glass powder, oven firing it (as high as 820°C for top-level grand feu dials), then successively painting with a suspension of coloured glass powder, fired one colour at a time. Because the enamel shrinks, several firings are required to ensure all the crevices are filled. This means the risk of microfissures increases every time, potentially ruining all the hard work. It’s a fiddly and tense process, with just a few degrees’ leeway in oven temperature yielding a frustrating wastage factor. Watchmaking employs a number of different methods for decorative enamel finishes.

Champlevé: the oldest enamelling technique. Cavities are milled into the dial and filled with opaque or translucent enamel. After firing, the piece is sanded smooth and glazed.

Cloisonné: fine ribbons of metal are fixed to the dial to create the lines of a picture. The cells are filled with enamel and fired in the kiln.

Plique-à-jour: similar to the cloisonné method, but once fired, the thin copper backing is dissolved in acid to leave a translucent stained-glass-window-like dial.

Paillonné: paillons are small gold-leaf motifs, such as flowers, leaves or stars that are placed between two layers of enamel to decorate a dial.

It’s all about colour in watchmaking right now, especially in one particular guise. Whether you call it ombré (shadow), fumé (smoked) or simply gradient, dials where the colour darkens outwards or inwards can be found everywhere. Fumé gives a sense of depth and mystery to the simplest design. You’ll find it on Jaeger-LeCoultre’s recent cobalt-dial Polaris Date as well as Zenith’s tobacco-hued Radar, which was conceived in cahoots with Bamford Watch Department and inspired by the so-called tropical patina you get on well-worn vintage pieces. The fabrication technique involves spraying the shadow onto a rotating dial that’s already been coloured, producing a unique result every time. Simply by adjusting the speed of rotation of the dial and the power of the spray, you can have a smooth gradient or something that simply has a darker rim.

Guilloché isn’t a specific watch term, it just refers to a repetitive architectural pattern of intersecting or overlapping spirals or other shapes. Although beautiful to look at, it originally had a practical purpose, as a quick way to eliminate any material defects, as opposed to polishing them out.

The craft requires a rose-engine turning machine that uses hand-operated lathes, all of them more than a century old. With careful application of maths and mechanics, the dial is rotated in a pre-programmed pattern as you apply the cutting bit. Requiring precision to 0.1mm, the process depends not only on the machine, but the artisan’s sharp eye and steady hand. At Vacheron Constantin, one of the few brands that still guillochés by hand, 12 to 18 months of training are necessary to execute even the simplest patterns.