Movement finishing is part science and part art, mixed in with a dash of superstition. Few people have mastered the necessary techniques to finish parts by hand to an outstanding quality, and there exists a significant difference in the quality of finishing across the board. While it is undeniably a pleasure to look at, beneath the surface lies hard work and a significant amount of trial and error, and evidence of the watchmaker’s very personal approach. As a general rule, a vast chasm lies between the level of finishing one will see in commercial and hand-finished timepieces.

For certain brands and many independent watchmakers, movement finishing has become another mode of artistic expression. The surface of the movement is transformed into a canvas for experimentation, or used as a way to pay tribute to tradition, or tie together the watchmaker’s design philosophies. From the mastery of traditional techniques in Bernhard Zwinz, Daniel Roth, or Petermann Bedat’s work, to the modern twists found in the pieces of Sylvain Pinaud, Romain Gauthier, and Krayon, each bring a signature style in executing their movement finishing. In this piece, we narrow in on techniques that are specific to Swiss finishing, exploring the processes, challenges, and quirks in creating this art.

To start with, it’s important to get a sense of the kinds of metals and materials each of these finishing techniques are performed on. Traditionally, brass, gold, steel, or German silver (a specialist member of the brass family) are used, but modern watchmaking has expanded to include materials such as titanium, new alloys, or even silicon, sapphire, ceramics and metalloids – of which a few on this list cannot be hand finished. Traditional finishing is first performed on the chosen metal, then typically plated with thin layers of gold, palladium, or rhodium, whereas some brands (such as Winnerl) preserve the finished parts in their final, hand-worked state.

The basis of movement finishing relies on perfect surface preparation. Gaël Petermann, of Petermann Bédat, explains that a different approach is required for each material. “When you start to make an angle or anything similar you need to start from a smooth surface. So we use different materials to smooth the surface, then we polish at the end. For example, we use certain tools for black polish, but other tools for anglage. Even between materials, [such as] steel and brass, we use different tools or different diamond pastes. Each material requires a different method of polishing – for example brass is very soft, way softer than steel, so you can’t use the same technique.”

There are a few machines that are also staples in the workshop for movement finishing, such as lathes, hand-drills, and files, but a great degree of specificity exists with regard to each watchmaker’s preferred methodology, so there isn’t a universal list of tools that apply in every situation.

One of the most well-known types of movement finishing, the Côtes de Genève, also known as Geneva waves or Geneva stripes, needs almost no introduction. More usually placed on bridges, the effect produced is of undulating stripes that reflect light, creating the impression of delicate waves. No one knows exactly when this was invented, but we can reasonably guess that the technique originates from Geneva.

Quite a few sources suggest that this form of decoration also has a functional aspect, which Bernhard Zwinz, a master watchmaker and the founder of Winnerl, explains: “[The Geneva stripes] harden the microscopic exterior layer of the metal part, changing its molecular structure, thereby effectively sealing it against the effects of atmospheric moisture and the collection of dust particles over time and reducing the adhesive forces that might attract the collection of dust particles over time.”

There are three main aspects that are important when it comes to creating traditional Côtes de Genève. First, an accurate, microscopically adjustable flat machining table; second, a rotating grinding tool – usually made of boxwood or some other kind of hard wood; third, the grinding powder in a paste form composed of ground stone particles, usually created from diamonds.

In making the watches for his Winnerl Tremblage and Founder’s series, Zwinz had to make serious changes to his machine to achieve the required accuracy. “I had to overhaul and redesign my antique Geneva stripe machine, ensuring it could deliver a precision down to only hundredths of a millimetre,” he says. “This enhancement allows me to adjust up to eight axes, achieving the level of accuracy needed for flawless execution of the decoration.”

In terms of the other two requirements, Zwinz emphasises that his combination of wood and abrasive powders is historically accurate. “I had to make numerous experiments in order to establish an ideal set of variables for the grinding powder and wood to be used. This led me, ultimately, to the use of an extremely hard type of boxwood for the spindle, paired with diamond powder of a specific grain size.”

Zwinz then goes into detail into how he has refined the traditional techniques used: “For my Côtes de Genève, I always use a totally flat table with an x and y axis, with a very lightly inclined and rotating spindle positioned above it. Traditional watchmaking utilizes a wooden spindle topped with a fine grinding powder, able to create extremely fine and delicate lines. This traditional approach also demands that each part that will receive a Côtes de Genève treatment must be prepared in advance with a perfectly flat, polished surface before starting, because the graining I can achieve this way is so fine in structure.”

The finished product, a “perfect” Côtes de Genève, according to Zwinz, has an “an exacting 90° wave pattern exhibiting a flawless, flat appearance, having a width [exactly] equal to the radius of the grinding spindle.” Overall, applying this traditional method to a single baseplate is the equivalent of almost three days’ work for Zwinz, with each single Geneva stripe taking approximately 80 to 100 passes before he proceeds to creating its neighbour.

On the other hand, commercial watchmaking takes a different approach to the decoration, doing away with the human preparation and losing any fine definition. This whole process takes just under five minutes, underscoring the skill required for the traditional method. Although these commercial decorations look more uniform, Zwinz notes: “The rotating spindle is normally topped in coarse grained abrasive paper that creates deep 3-dimensional grooves in the metal which under close magnification looks as if the material has been roughly scraped off with a nail file.”

Zwinz’s Côtes de Genève is a masterful exercise in classical finishing, performed to his own exacting standards and with rigorous flair. However, there are other watchmakers who have decided to put their own spin on things. For example, when taking a closer look at the pieces produced under Daniel Roth’s workshop, Jean Daniel Nicolas, we see that the curve of the Côtes de Genève is more pronounced, giving the appearance of a semi-circle rather than a 90-degree angle. Another interpretation of the Côtes de Genève can be found within De Bethune’s work, which they have called “Côtes de Bethune”, which are symmetrically placed, with the circles opposing each other, moving outwards from the centre and possessing a specific slant.

An especially notable example is Krayon, a Swiss brand known for their complicated watches, and their artistic Côtes de Genève, which have a deceptively free-flowing appearance, but hold a far more complicated concept.

In keeping with their mathematical approach to watchmaking, their movement finishing also demonstrates this focus. Remi Maillat, the founder of Krayon, explains the process of creating the movement in very artistic terms. “In designing the movement, we always consider it as a painting,” he says. “When you look at a painting, you want to put your eyes somewhere that attracts your attention. For us, it’s a similar story. On our movements, we use different materials, creating reflections, textures, bringing out the different colours of the material or the metal to create that picture.”

Krayon’s work translates aspects of the natural landscape into metal, inspired by the workshop’s surroundings and the passing of time. “The overall shape that the Côtes de Genève takes on the Anywhere [timepiece] follows the sunset time of Neuchâtel over an entire year. We really wanted to express our attachment to the place we are located,” Maillat says. “The shape of the bridge is also based on Lake Neuchâtel. This was a result of our studies and tests with the Geneva waves, as we wanted to make it completely different, and our experiments allowed us to do more than just straight lines. We used this to highlight the function of the watch, and reflect the nearly symmetrical geometry of the complication.”

Although Krayon weren’t able to share the exact methods by which the Côtes de Genève is created – some movement-finishing methods remain closely guarded trade secrets, even today – they were able to share with us how they calculated the overall curvature of the movement decoration. It essentially is a literal translation of the recorded sunset time data, transformed into mathematical waves and combined to create an artistic interpretation.

Maillat describes the process: “We put the data into an Excel table and used the file’s parameters to define the Geneva stripes, as well as the rotation. Essentially, a cylindrical tool is used to create Côtes de Genève, moving across the surface of the bridge to create the shape. So, what you see visually is the diameter of the tool, combined with rotation and movement. This is combined with the angle of the tool as it touches the bridge.”

As demonstrated by the example above, the overall quality of watch finishing is not just determined by how well each individual finishing is executed, but how each aspect of the finishing comes together in a harmonious way. This includes juxtaposing different textures, layering various types of finishing, and considering the overall effect.

Naturally, this poses several challenges. Among the things to consider with Krayon’s Côtes de Genève is how this technique interacts with the other types of finishing and the danger of accidentally ruining several days’ worth of work on the bridge. Maillat highlights that they had to be particularly careful when placing the Côtes de Genève around the edges of the component. “There is a strong criterion which is the edge of the anglage,” he says. “If you observe this edge along the surface of the bridge, you will see a step. We wanted to avoid that step to avoid damaging the anglage.

“The process is very tricky as with our method, if one bridge is damaged, then basically all of them are damaged, because they are at the same level and have the same thickness. A lot of movements are damaged in the process because there are so many factors involved.”

Also known as chamfering or bevelling, this technique involves creating a 45-degree angle on the part, resulting in the clean and sleek edges that you see throughout the movement. These edges catch the light, allowing each component to seem more ‘alive’. Traditionally, these edges are polished with the same technique that we have described above, with wood and a stone paste. Today, some parts arrive ‘pre-angled’, but the final touches and real quality are still derived from the watchmaker’s personal touch.

One of the first independent watchmakers of the modern era, Daniel Roth, still performs this technique entirely by hand. He explains that there is a significant difference, as he is able to achieve much sharper angles compared with modern methods. “To angle the components, watchmakers now use ‘tourêts’, a kind of small grinding wheel fixed on a small lathe, which provides an acceptable anglage much faster, thus a criterion of profitability,” he says. “Personally, I am unfamiliar with this technique; I have stuck with handcrafted anglage, which takes much more time but yields exceptional results in quality, radiance, and brilliance. The angles are sharp and precise, not rounded as with a grinding wheel.”

Roth explains that his methods have been carried on over generations, as he was taught to perform this technique by older watchmakers. However, the tools that he uses, and the entire process is based on his own extensive experience and experimentation with what works – down to creating the tools themselves. He says: “I use tools that I have designed myself for this purpose, particularly the files that I make from mild steel on which I create appropriate light grooves. I also use a strong diamond paste to define the angle and then progressively softer pastes to enhance the brilliance.”

On the other hand, there are watchmakers who use a combination of modern and traditional techniques to produce an evolved style. Romain Gauthier is one of these; the independent brand uses a mixture of techniques on the bridges of pieces like the Continuum. The angles are bevelled, but are sandblasted to give a matte, rather than a polished, finish. Notably, many edges found in their movements have a rounded, rather than right-angled, look – a slightly different type of anglage called bercé.

This style of anglage has a rounded look, which is much harder to create because the angle is not a straightforward right angle. It is usually created with a file, then polished with wood, following the typical method. However, the polishing stage takes a significantly longer time because it must be polished from many more angles to create the shape, and it is extremely difficult to make this perfectly even. Furthermore, because there is more surface area reflecting light, it is immediately evident when the angle is not perfectly shaped or if the polishing is not even.

Gauthier goes into some detail about the decision to use this style, crediting it to discussions with a notable fellow watchmaker from the Vallée de Joux. “Back then, I went to see Philippe Dufour, a friend of mine, who told me, ‘You should do the best, so do the rounded bevelling. It will be nicer, the reflection of light will be greater, and it’s more beautiful on the eyes,’” he says.

“For us, the difficulty was with the precision. The bevelling was not strictly at 45-degrees, as we used a bercé-type bevelling. With this type of rounded bevelling style, it’s far more complicated, because you don’t just create a straight line with your tool, but you have to move it all around the sides of the part. When you polish it, you have to approach it like polishing a sphere.”

Another term that often appears when describing the specific part of a movement is “inward angle”, which refers to the way two bevelled edges which meet together, curving inwards into the part, rather than away from it. A lot of skill and dexterity is required to make one of these angles, because the small space of the angle means that the other side can be very easily damaged by the tool used to polish the other side of the angle, completely ruining the work. Its reputation is well-earned, given the fact that it is still impossible to make such angles with a machine. This has become a way to emphasise how impressive the level of finishing is, with the higher the number of inward angles, the more accomplished and masterful the finishing is deemed to be.

While perlage is often (incorrectly) equated to circular graining, and the terms seem to be used interchangeably, we are of the opinion that there is a distinction between them. Perlage refers to a specific technique where small overlapping circles called “pearls” are created through a rotating tool, giving the part (usually the baseplate) a very textured and complex look, whereas circular graining has many different forms and can be used almost anywhere in the movement, even on dials and bezels.

Nonetheless, the application of these terms is rather fluid, especially as watchmakers experiment with reinterpreting these traditional techniques. As with Côtes de Genève, perlage offers a similar type of protection to the movement with regards to the adhesion of small particles over the course of time.

Zwinz’s use of perlage again follows a very traditional method, but his focus is turned towards precision and clean execution, pushing the limits of how accurately and perfectly this finishing can be executed. As a form of treatment through polishing or abrasion, largely the same types of tools are used here. Zwinz explains: “I refined my experiments with Geneva stripes, and for perlage I found that a softer variant of the same boxwood family, also paired with abrasive powder, gave ideal results.”

To create the pattern, the process requires a steady hand and the correct placement of the tool on the surface. Zwinz also goes into some detail about how his technique distinguishes itself from the rest. “I move the tiny grinding spindle to the workpiece surface, which allows me to selectively grind only the visible part of the pearl without overlapping the last executed pearl,” he says. The result is extremely subtle but visible to the learned eye, making the perlage perceptibly ‘glow’. This is because each new pearl’s visible surface is not ‘biting’ into the previously treated section of the preceding pearl. This technique gives me the ability to create perlage down to a diameter as fine as 0.80mm.”

The decoration of watch wheels can take many forms, and the above styles are just general terms for the types of finishing you might observe on these wheels. At its most basic, circular graining is a technique where each concentric circle is a closed one that radiates outwards, giving the impression of tree rings, and do not overlap.

However, another version, called “soleilage” or snailing, has curved lines radiating outwards in the style of a sunburst, all curving in the same direction. Additionally, on larger wheels, something called a “double snail” is possible, where a first small circle of snailing is nested within another outer ring of snailing, with both curving in opposite directions, which creates a more complex effect when light hits the wheel.

Another style worth mentioning is basic vertical brushing, which uses straight lines that radiate outwards, providing a satin-style finish, which looks very smooth and clean. This technique is more often used on moving parts, such as in chronograph movements.

Broadly speaking, we can consider a matte finish to be the opposite of polished in terms of their looks, although they stem from a similar technique. The matte texture absorbs rather than reflects light, giving it a subtle appearance that can be used in contrast with polished surfaces or throughout the movement to create a futuristic, sleek character.

An example of this contrast used to great effect can be found on Sylvain Pinaud’s Origine, whose movement features a large matte-finished bridge. According to Pinaud, this differs very slightly from the traditional matte look. “I call it grainage, which is obtained by gently rubbing the part on a plate with abrasives,” he says. “I use different abrasives to create a different grain between the different stages of the watch. I chose this process because it’s less destructive than sandblasting and other machine graining. I use this style because I find it more delicate and soft-looking, and it blends well with the round shapes of the movement’s architecture.”

A very different style of matte finishing has been adopted in the watches of Romain Gauthier. Gauthier explains that they wanted to do something different to capture collectors’ attention. “The platinum version of the Prestige made use of a matte finish on the bridges,” he says. “This is a very classical level of finishing and the effect is produced by placing powdered stone on the part and moving it back and forth. Depending on the dimension of your stones, you can get a rougher or smoother look, so you have to change dimensions as you go along to find the best type of stones that will fit with the type of bevelling.”

He also says that there are several different ways of achieving a matte surface, with varying levels of appearance. On the C series, the matte surfaces are placed within the finger-styled bridges in a sunken recess, sealed by smooth, matte borders. Gauthier says: “There is the matte that we do by hand, but there is also the super-smooth matte, which is done with water and stones, or waterblasting. But it’s not just blasting the part – you have to prepare all the surfaces by hand before that.

“[I wanted] to reproduce a kind of matte effect but with a method of hand engraving. We started working with a friend who is a professional engraver and tried to obtain something nice in terms of texture. In a way, the goal is to reproduce the matte effect done with the laser, and this is how we do it today. Everything is done in-house. Many of our movements are made from titanium, which presents its own challenges as a very tough metal, but one that resists corrosion.”

Meanwhile, modern ways of finishing, by machine, are another topic of contention. While machines can perform the finishing techniques, there is always a less sophisticated feeling about it, and certainly a more impersonal feeling compared with something finished by hand. Gauthier says, “Today a lot of brands use matte finishing, but it’s done by laser. The problem with this is that the laser techniques are used by everyone, so you find watches at $2,000 with that finishing, as well as watches at $100,000 with the same finishing. So where is the added value? It’s dangerous if you want to do the same for an expensive watch – people will start to notice and say, ‘Oh, look, it’s the same finishing as this brand, which is not as expensive. So why are they charging that level of money?’

“It's important to bring the collectors something refreshing, something different, and with the value added through handwork and real craftsmanship, that doesn’t just depend on laser technology. We seek to improve all those things, either through the techniques or the use of material [such as] titanium.”

This particular technique has a reputation for being one of the most difficult types of finishing to perform, as well as the most time consuming. It is only used on steel parts and must be done on a completely smooth surface. Because it reflects light so perfectly, the surface appears black when viewed from certain angles. This type of finishing is most commonly seen on the screws embedded within the movement, and can be found on bridges, or other parts as well.

Achieving a perfectly flat, unblemished surface is no small task. One of the biggest problems that often crops up, says Petermann, is that the polish makes even the tiniest scratch incredibly visible. “When you play with the light, you need to see that your surface is completely black, and the real difficulty [with] that is if you have a scratch – even a little scratch – you can see it directly. This is because the scratch will be white, and there is a big contrast against the black surface,” he says.

Creating something “perfect” then becomes a question of learning how to catch and remove these scratches, with improvement only coming with time and experience.

Pinaud says, “A perfect black polish can only be obtained by human hand and cannot be mechanised. The piece must be polished for a long time on a pewter plate until a perfectly flat surface is obtained. This is even more difficult on large-surface parts such as the balance bridge. For black polished parts, you have to bevel and stretch the fields beforehand, then do perlage on certain parts, before finally creating the black polish, which can take up to an hour. On the Origine, the complete decoration of the movement takes about two weeks.”

Petermann describes a similar process for Petermann Bédat’s watches, which are slightly different because of their use of a softer material. “We use ebony wood to bevel sections, then put it in a small hand motor with polishing paste. When you turn the wood on it, it will polish the section over time. Because we use German silver, we just use polishing paste – we don’t use another material to soften it. We use very thin sandpaper to soften it and create a different dimension of the grain, and then in the end we polish it with the wood.”

There are many reasons to use this type of finishing and black polish significantly enhances the visual aesthetic of the watch. Pinaud explains that he has carefully chosen which parts to use black polish on in his watch Origine “because it's the perfect contrast with the texture of the graining. I find that blending these different textures allows me to play with light and brings the architecture of the movement to life.”

The time taken to perform such polishing is a significant portion of the overall time taken to finish a piece. Pinaud says that it can take up to six hours to bevel and decorate a large bridge. Petermann also emphasises how long the process can take, as well as the experimentation needed to find a happy medium between quality and the time taken to produce the finishing: “Of course, we lose a lot of time because normally with straight graining, it takes five minutes – well, if you’re really bad at it, then it takes five minutes. But with black polish, it takes around 30 minutes, and that’s considered fast. With more parts, you have to spend more time on it. Sometimes, with the complexity of the parts, it’s difficult to achieve a flat surface everywhere.”

Rather intriguingly, there seem to be many superstitions surrounding black polish – highlighting its very personal and particular nature, as well as how difficult it is to finish to a high quality. Every watchmaker has their own approach, with no technique being a universally applied method. Petermann says: “People normally say when it’s raining outside the air is too humid, so you can’t do black polish, and other things like that. There are also superstitions involving the paste used. A lot of people use diamond powder, but others use ruby or sapphire powder, mixed in with different oils. Honestly, when you finally find a solution to make a good black polish, you just stick with it. You don’t try anything else.“The biggest problem with watchmaking is that every watchmaker uses a different technique. I remember when I was at Lange trying to make black polish on the gold chaton. I asked a watchmaker for help – I said that I still had a lot of scratches, what do you do? He showed me what he did, then I went to another watchmaker [and] he showed me another technique. In the end, I [used] another technique that worked for me. So yeah, if it works for you, fine, keep the technique, but if it doesn’t, just try another one.“

Much of this personal approach can be applied to all movement finishing executed by hand. The watchmaker is just as crucial in the process, bringing their own style, personality, and approach to the art. As well as focusing on each individual technique, they also have to consider the movement as a whole, choosing which finishing style to apply where, ensuring that things blend well together, and stepping back to view it, as Maillat says, as a painting.

It is these differences that give each hand-finished movement a unique signature that collectors have only just begun to appreciate. Zwinz says, “As a watchmaker, it’s a pleasure for me that serious watch collectors are becoming more and more interested in the different finishing techniques used in high-end watchmaking. The only issue with such knowledge – just as the case with art, fine wine or high-performance sports cars – is that there is a vast difference between the craftsmanship you will find in the commercially produced wristwatches we see everywhere in the industry, and the kind of hands-on approach to watchmaking that fully respects traditions that go back centuries.”

The whole endeavour is perhaps best summed up by Roth, whose long and illustrious career brings a quiet wisdom. “[Movement finishing] is a sculptor’s work on an infinitely small scale, which requires great dexterity and infinite patience to achieve perfection,” he says. “The greatest difficulty is forgetting the passing of time.”