The PHILLIPS Hong Kong Watch Auction: XX takes place on 23-25 May, 2025, at our West Kowloon headquarters. The auction includes more than 280 of the world's finest watches – and though we are loath to boast, we truly think it's one of the best catalogues we've ever put together. We'll be highlighting a number of the most interesting lots and stories featured in the sale right here, including all the timepieces highlighted below.
– By Logan Baker
Sertissage
Sertissage is what turns a timepiece into a piece of jewelry. It’s not just about decoration. It’s about technique, precision, and taste. And like so many things in watchmaking, it’s often invisible unless you know where to look.
Let’s start with what sertissage actually involves. At its core, it’s the process of setting gemstones — diamonds, sapphires, rubies, emeralds — into the metal surfaces of a watch case, bracelet, dial, or bezel. There are many ways to do it: pavé, claw, grain, invisible setting, channel setting... Each one demands a different set of skills and serves a different aesthetic. But the goal is the same: secure the stone, enhance its brilliance, and do it in a way that feels natural to the design.
In the best examples, the gem setting looks effortless. But behind that effortless look is serious work. A skilled setter (or “sertisseur”) has to consider symmetry, proportion, alignment, and how the stones interact with the light. They work under a microscope, sculpting the metal around each stone with tools that haven’t changed much in a hundred years. One wrong move, and you’ve chipped a diamond. Or worse, you’ve ruined a dial.
If you’re picturing some high-tech robot setting stones with mechanical precision, you’re in the wrong room. Most of the top brands still rely on human hands. That’s especially true when the layout gets complicated — like snow setting, where diamonds of different sizes are placed as densely as possible with no discernible pattern. That kind of work isn’t just technical. It’s artistic.
And it’s often overlooked. When we talk about craft in watchmaking, we usually go straight to movements, finishing, complications. But gem setting deserves a seat at the table. It requires the same obsessive attention to detail, the same reverence for tradition, and the same pursuit of perfection.
Enamel
Watchmaking is full of old techniques that feel like they shouldn’t exist anymore. Not because they aren’t beautiful, but because they’re just too damn hard. Enameling is one of them. It’s fragile, temperamental, expensive, and time-consuming. And yet, for collectors who care about craft, enamel dials are about as good as it gets.
Enamel is basically powdered glass fused to a metal surface using high heat. That sounds simple. It’s not. The process takes hours, sometimes days. And it’s brutally unforgiving — one mistake, one hairline crack, and you’re starting over from scratch. But when it works, the results are stunning: rich, lustrous color with a depth you don’t get from lacquer or paint. Enamel catches light differently. It glows.
There are a few different techniques you’ll come across: grand feu, cloisonné, and champlevé are the big three. Let’s break them down.
Grand feu (French for “great fire”) is the purist’s choice. It’s just enamel and heat, nothing else. The artisan applies several layers of enamel powder to a metal base, firing each one in a kiln at around 800°C. Between firings, they smooth and clean the surface. The result is a deep, even tone — usually white or black, though some makers experiment with color. Grand feu dials look simple, but they’re anything but. A lot can go wrong in the oven. Warping, cracking, bubbling... it’s a delicate dance between control and chaos.
Cloisonné is where things get decorative. Here, the artisan uses thin wires — usually gold — to outline a design on the dial. Those little wire cells (called “cloisons”) are then filled with different colored enamel powders. It’s like stained glass, on a tiny scale. After multiple firings, the surface is polished smooth. Cloisonné dials tend to be colorful, narrative, and detailed. You’ll see them in scenes of dragons, world maps, flowers, you name it.
Champlevé flips the script. Instead of building walls with wire, the artist carves recesses directly into the metal dial. Those cavities get filled with enamel, then fired and polished just like cloisonné. The effect is more subtle, with the metal serving as both canvas and frame. Champlevé often feels more sculptural. Brands like Cartier and Ulysse Nardin have done great work here — especially when it comes to their metiers d’art collections.
There’s also flinqué, which combines enamel with engine-turning. First, the dial is decorated with a guilloché pattern — those hypnotic, repeating waves cut by a rose engine. Then, a translucent enamel layer is applied over the top and fired. The enamel sinks into the grooves, adding color without hiding the texture underneath. Think of it like mood lighting for metalwork. Breguet, Fabergé, and even modern-day Omega have used flinqué to great effect. It’s less pictorial than cloisonné or champlevé, but no less refined.
Skeletonization
At its core, skeletonization is about subtraction. Take a finished movement — already precise, already functional — and start cutting away. Carve out bridges, hollow out plates, reduce the metal until what’s left barely holds together. It sounds reckless. It’s anything but.
Skeletonization sits at the intersection of engineering and art. You’re not just exposing the movement; you’re reshaping it so that structure and beauty become the same thing. The goal is to remove as much material as possible without compromising function or rigidity. Done right, it turns the movement into a miniature sculpture. Done wrong, it turns it into scrap.
This is not new. Watchmakers have been skeletonizing movements since the 18th century, mostly as a way to show off their skills. It was a flex: “Look how little material I need to keep this running.” But over time, the aesthetic appeal took center stage. A skeletonized movement invites you to look through the watch. To see the escape wheel ticking, the mainspring coiled tight, the balance swinging back and forth like a metronome for the wrist.
That transparency demands attention to detail. Every visible surface has to be finished — anglage, perlage, polishing — because there’s nowhere to hide. In a traditional movement, you can get away with leaving the underside of a bridge rough. In a skeletonized movement, that would be criminal. The light will catch it. Your eye will find it.
There are a few ways to go about it. The traditional approach is hand-skeletonization: an artisan uses a jeweler’s saw, files, and engraving tools to manually open up the movement. It’s slow, risky work, often taking dozens of hours for a single caliber.
Then there’s the modern way: design the movement from the ground up with skeletonization in mind. Here, it’s less about carving out and more about building up — using openworked architecture from the start. These movements feel technical, angular, and aggressive.
Of course, not everyone loves skeleton watches. Some people find them too flashy, too fussy, too hard to read. Fair enough. But even the skeptics have to respect the difficulty involved. You’re taking a tightly engineered mechanism and asking it to look good naked.
At its best, skeletonization strips away everything unnecessary and leaves you with the essence of watchmaking: gears, springs, wheels, levers — all balanced in open air.
Guilloche
Guilloché is one of those words that gets thrown around a lot in watch marketing, often with little explanation beyond “pretty engraving.” But for those who know, guilloché is something special — a centuries-old craft that turns flat metal into living texture, using a machine that’s closer to a musical instrument than a tool.
At its simplest, guilloché is decorative pattern engraving done with a rose engine or straight-line engine. These are hand-cranked lathes — antique machines, usually dating back to the 19th century — that use a system of cams, gears, and pressure to cut impossibly precise patterns into metal. The results look almost digital: interlocking waves, sunbursts, barleycorn textures, basket weaves. But there’s nothing digital about it. This is human craftsmanship, guided by feel, rhythm, and patience.
The watchmaker (or more accurately, the artisan guillocheur) has to hold the tool steady, feed the metal consistently, and listen to the subtle vibrations of the machine. It’s tactile. You feel when the blade is cutting right. One slip, one second of distraction, and the dial is ruined. There’s no undo button.
You’ll most often see guilloché on dials — classically on silver or gold — but it can also appear on movement components, cases, even crowns. Brands like Breguet, which has deep historical ties to guilloché, have kept the tradition alive with dials that still come off hand-operated lathes. Other houses, like Voutilainen, Roger Smith, and the late George Daniels, treat guilloché not as decoration, but as signature. You can spot their work from across a room.
Of course, there’s also stamped guilloché — patterns pressed into metal using a mold. It’s faster, cheaper, and easier to mass-produce. You’ll see it on entry-level dials that want the guilloché look without the guilloché price. And to be fair, some of those stamped patterns look great. But once you’ve seen real guilloché under changing light—how it catches reflections and pulls your eye into the dial’s surface — you know the difference.
Engraving
Engraving in watchmaking is one of those crafts that lives just under the surface. You won’t find it on spec sheets or technical charts. It doesn’t improve timekeeping or water resistance. But when it’s there, it adds a layer of soul you just can’t replicate with a machine.
At its heart, engraving is simple: cut a design into metal. But like most things in watchmaking, the simplicity ends there. There’s machine engraving (fast, clean, consistent) and there’s hand engraving (slow, imperfect, alive). We’re here to talk about the latter.
Hand engraving takes nerves of steel and a steady hand. The artisan — called an engraver, or more precisely, a “graveur” — uses a tool called a burin, a sort of hardened steel chisel, to carve into the case, dial, or movement bridge. There’s no guide, no safety net. It’s just pressure, angle, and instinct, repeated stroke after stroke. Some designs take days. Others take weeks.
You see it most often on the case: scrollwork along the flanks of a pocket watch, or a monogram hidden between lugs. But engraving can show up almost anywhere. Some brands go deep — engraving bridges, rotors, even balance cocks. Others focus on dials, where the line between engraving and art becomes razor-thin. That’s especially true with repoussé and relief engraving, where the metal is sculpted to create raised designs with texture and depth.
Of course, engraving has always had a personal side, too. Casebacks with initials, dates, dedications. Military watches marked with service numbers or units. This is the paradox of engraving in watchmaking: it adds no mechanical value, and yet it adds immense emotional weight. It’s permanent. It can’t be undone or retracted. And that permanence means something.