Geneva watch case hallmarks, the key to who produced your watch case.

As we have already discussed before, the Swiss industry has been very structured in the production and registration of their watches since well over 100 years. Therefore chances are that when you own a swiss made gold vintage wristwatch, you will be able to uncover some of its history from the inside case back. At Perceptions, our focus is on the most exclusive vintage watches. For brands such as Patek Philippe, Audemars Piguet, Vacheron Constantin, Jaeger-LeCoultre, Omega and many more the cases had to be the best of the best. Where does the best of the best come from when we talk about gold watch cases? There is one place that housed all the important makers, the city of Geneva.

The fragmented industry of watch production

When most people think about the watch industry, they think about the big brands. Nowadays it would be more or less correct to say that the big Swiss brands make their watches inhouse, although we often still see standard caliber movements come from external manufacturers. However, over the course of the last century, those brands were simply the face of work provided by lots and lots of different companies. It would not have been unusual if the case, movement, hands and dial would have all been produced by a different company. The big brands simply chose from big catalogues what they liked and what would work well together. They themselves would mainly focus on movement calibers and the construction of the final product. Would these practices lead to an inferior product? On the contrary, this lead the incredible innovation. Every single company did what they knew best. A case maker would make cases, a dial maker would focus on dials, and so on. As there were so many of these companies, there would be a lot of competition. This in turn would lead new designs and ideas all the time to outsmart the competition. This is why we see such an incredible array of models when looking at vintage watches, as new ideas were available to the brands at all times. Nowadays brands focus on a core collection and do not go too far outside their comfort zone. Back in the 1940’s and 1950’s for example you would find extraordinary designs. Another idea that is hard to grasp for people new to vintage watches is that there was no designer drawing up what a new watch had to look like, you simply worked with what was available. Don’t feel bad for them though, as what was available was absolutely amazing.

Who made your watch case?

If you can simply read the brand name on your dial and be happy, that’s very healthy. I would even encourage you to not finish reading this. For some this could be just the start though. Once you really get into watch collecting, you will notice that part of the fun is uncovering more and more information about your vintage timepieces. With the limited documentation available the community is uncovering the history of the Swiss watch industry one watch at a time. There is seemingly no end to this. When comparing the current state of the collector community to the one we saw 10 years ago, we have come so much further. For most brands there is now an extensive history available with a simple internet search. New things are still found and shared by the community on a daily basis. How is this new information found? Sometimes trough old ads, sometimes by looking at new old stock watches or sometimes by simply looking at the inner case back of your watch. It is there that you can find a so-called hallmark or Poinçon de maître. This will tell you who has produced your watch case. Because wouldn’t it be fair and respectful if we look at the company who actually produced these extraordinary cases, instead of the brand that selected them from a catalogue?

The Geneva Key

Since 1934 it was mandatory to use a makers hallmark for all Geneva based case makers. Some of them started using them well over a decade earlier though. This regulation was put in place to control the quality of the work. The hallmark used is a key with a number in it. This key guarantees that your watch case has been produced in Geneva and is more than 0,3mm thick. Some of the watches use an additional mark to show exactly who thick the case is. An example of such a mark can be found below. The number inside the key will lead you directly to the maker of your gold watch case. You might be surprised not to find a key inside your watch case, but remember, the Geneva Key was only used for the best cases in production. As Geneva would be the most prestigious place in the production of these cases. Other hallmarks can lead to different places in Switzerland or even different countries. But for this article we focus on Geneva.

To the left here an example of a Geneva Key hallmark is visible. The number inside the key is 23, which leads us the famous Geneva case maker Eggly et Cie.

Apart from the Geneva Key hallmark, some other markings are visible. Although not important for the scope of this article, we will quickly go over them. The 18k 0,750 designation shows us that we are dealing with 18 carat gold here, or 75 percent pure gold. The little woman’s head is called the Helvetia hallmarks proves the case is tested 18k gold.

An overview of case makers

We will now present you with a list of case makers and their numbers. This can be helpful in case you want to know who made your case. I have said it before and out of love for vintage watches I will say it again, do not open watch cases if you do not have the appropriate knowledge. Any skilled watchmaker specializing in vintage watches, will be more than happy to help you. Irreversible damage to watches is done on a daily basis because people decide to open watches themselves. If after looking at the table you still have questions, feel free to send us a message. If you would like to sell a watch bearing the Geneva Key hallmark, please use the form on the website.

Praise the ones who paved the way

To my knowledge the first person to make this information available on the internet has been David Boettcher. This table is a simplification of his work and is placed here to have the information available on the website. Make sure you visit Mr Boettcher’s website vintagewatchstraps.com. His website is full of incredibly detailed information for those who are deep into watches.

Practice your poinçons

Below are a few pictures of case backs stamped with the Geneva key hallmark. Are you now able to find out who produced them? You are now one step closer to becoming a watch expert.