All about Gullioche watch dial
If you are intrigued by fine watchmaking, you might have come across beautifully patterned watch dials. These intricate fine lines etched on a dial are carved using a technique called guilloche. The watchmaker can create a guilloche pattern with two or more lines that intersect at specific points (known as "nodes"), creating an effect that looks like a series of waves or circles. The origin of the technique is unknown, but most watchmakers say guilloche was invented by a French watchmaker named guilloche in 1812.
Typically, skilled artisans apply hours of technique to plan and create precise lines forming specific patterns on metal. There are a few ways to do this. Traditionally, guilloche is performed by hand with tools such as a rose engine, but there are now computerised ways to get the same effects. When you look at a watch, apart from the overall aesthetic, much of its value comes from how it is made. Therefore, knowing how the guilloche patterns are crafted on the watch you desire can help you decide on a purchase. In this article, we examine the various techniques used in watchmaking to create fine guilloche designs.
- Using engine turning or a rose engine to produce guilloche patterns
Engine turning, also called the rose engine, is one method of producing guilloche patterns on metal. This method uses a tool called the rose engine lathe, a mechanical machine resembling a sewing machine. It is a specialised geometric machine with a rosette or cam-like pattern mounted on the spindle. The tool is controlled by moving against a cam follower(s) while the lathe spindle rotates. The resulting pattern has a circular shape that resembles flowers or complex, symmetrical, multi-node geometric patterns. No other ornamental lathe can produce such flower-like patterns, hence the tool's name.
The rose engine is best recognised for its role in decorating metal objects such as watches, clocks, and snuff boxes. The patterns produced are applied directly to an object's surface or with a mould.
A rose engine lathe is not a machine in the industrial sense of the word. Rather, it's a mechanical tool that is not powered. The craftsman uses one hand to turn a crank which moves the workpiece. Using the other hand, he pushes the carriage bearing the chisel that engraves the material. Therefore, the "engine" is just a tool that permits the craftsman to be meticulous and work steadily. Since the craftsman cuts the lines one after another, skill and aesthetic sense is crucial. The cranking speed, the pressure exerted on the tool, and the precise positioning of the motif are all decisive parameters for the result. Therefore, with the rose engine, the guilloche pattern depends on the craftsman's attention to detail and handiwork.
Pros and Cons of using engine/rose-turning for watchmaking
Therefore, one advantage of using a rose lathe to create decorative patterns is that you can create very unique, intricate designs on a watch dial. It also can be used on many different types of metals and alloys, including silver and gold. After etching using a rose engine, the artisan can use other techniques, such as engraving or etching, to create even more intricate patterns.
However, engine turning has some drawbacks as well. For example, it requires specialised tools, which require much work to purchase. According to Watchprozine magazine, the last rose engine lathes and straight-line engines were manufactured in the 1930s. A watchmaking company that wants to offer customised rose-engine decorations may find it almost impossible to get one of these antique cast machines. Furthermore, the final result also depends on the skill of the artisan. Since few artisans specialise in using the rose engine nowadays, you will have to look for master artisans who can produce pieces using the tool. It will also take a very long time. Because of these drawbacks, a rose engine turned guilloche watch can be time-consuming and expensive. A watch company that offers customised guilloche patterns using rose engines will have to equate the effort to its cost of production, which reflects in a higher price for the watch.
- Using CNC machining for guilloche patterns
The second method, and commonly seen in luxury watchmaking nowadays, is to use CNC (Computer Numerical Control (CNC) machining for guilloche patterns. These machines typically have design software where the watchmaker can upload a guilloche pattern. Once uploaded into the system, the machine is computer-controlled. The CNC has a rotating graving bit or a spring-loaded drag engraver to cut the patterns into the metal surface. As CNC machines become more sophisticated, they can achieve similar artistic rose-like designs like the rose engines.
Pros and Cons of using CNC machining for guilloche
The essential advantage of using a CNC machine is that one can achieve beautiful geometric patterns without the manual effort of an artisan. The machines are also often compact enough to meet the needs of small watchmakers. Besides, the ease and speed of creating guilloche patterns using CNC machines mean watchmakers can lower production costs for the watch dial. This reduced cost, however, does not mean that the watchmaker sacrifices attention to detail. Overall, it's a win for the consumer as you get beautifully patterned luxury watches at a lower price, but not a lower value.
The only downside, however, if you want a genuinely detailed pattern, the skeleton will need more personalised touches hand engraving gives. With a rose engine lathe, the artisan may craft rounded ends or leave irregularities that are painstakingly chipped away. Some watch collectors who are purists may prefer spending a lot to get that level of detail. That said, unless you look at it under a magnifying glass, it's impossible to spot these tiny imperfections from a distance.
- Using metal stamping for guilloche
Metal stamping is a manufacturing process that converts flat metal sheets into specific shapes to create a metal die. Metal stamping guilloche uses a metal die to imprint patterns. The process is similar to engraving, but instead of cutting into the metal watch face, the stamping action presses the design into the surface. Stamped dials is possible to achieve the look of guilloche. What happens is that a flat metal dial with a pattern on it is pressed onto the watch's surface. The result creates elevated and lowered surfaces. As such, metal stamping requires less input from a designer. This is the most cost-efficient way compared to rose-engine or CNC-making guilloche patterns.
Pros and Cons of using metal stamping for guilloche
Stamped metal dials are supposed to have a flat appearance because the stamping process dulls the metal. Stamped or pressed dials cannot be produced with the finely incised lines that characterise true guilloche and cannot mimic the fineness of the real deal. The final result is a dull surface that could look more aesthetically pleasing and does not has the depth, although it does achieve a patterned appearance. An experienced watch collector can also spot the difference between a metal-stamped guilloche pattern and one created using a rose engine or a CNC machine.
ConclusionWhich of the three techniques above is the best way to produce guilloche? The answer is there is nothing innately 'good' or 'bad' about preferring one method over the other. Using rose engines to craft guilloche patterns is rare as it requires a master artisan. The final result may be visually more detailed and sharp. However, the cost and effort are prohibitive high. CNC methods of guilloche making are now so advanced even large watchmaking companies use these machines. It's much faster and provides the same level of detail that traditional methods achieve. While less popular due to design limitations, metal stamping is sometimes used in many popular watches. It lowers the production cost, resulting in a more affordable watch.