r Crott’s book is much more than just another book about watchmaking. Unusual in more ways than one, it is the first to deal with watch dials. Isn’t that astonishing? It is also a fantastic toolbox into which readers can delve according to need. “Richly illustrated”, to use the consecrated phrase, Helmut Crott’s book is also a masterstroke: it informs – or rather teaches – without boring the reader.

The first edition having run out in just a few weeks, the 2023 reprint (available in English and French) is proving difficult to find. This bestselling work fills an incomprehensible gap in a vast horological bibliography in which monobrand works and works dedicated to chronometry abound.

“I have discovered what I now know to be true: the dial is a key factor in determining the beauty and value of a watch: it is the very face of the watch”: with these words in the opening lines of his work, Helmut Crott puts the role of the dial, too long overshadowed by the technology of watchmaking, back in the spotlight.

Cover of “The Dial” by Dr Helmut Crott

In a methodical presentation divided into three chapters (the story of dial-makers Stern, the making of a dial and, lastly, a selection of legendary and classic dials), the author takes readers gently by the hand and invites them to apprehend all the aesthetic nuances that differentiate a grained, opaline and sand-blasted dial. Azurage, cabochon appliques, Zapon and cream of tartar are revealed to the curious like a marvellous repertoire of style of a forgotten language.

Why is the dial so important for a collector? Because when observing a watch, the first thing you see is the dial. Like the bodywork of a car, the dial is the first major feature to reveal itself to your eyes. It reflects the culture and taste of the collector.

In it, Helmut Crott paves the way for a whole new watchmaking culture. We interviewed him.

Roland Tille (left), Helmut Crott (centre) and René Baeriswyl (right), in the lobby of Manufacture F.P. Journe in Geneva.

Helmut Crott

Europa Star: Your work is divided into three distinct parts: the story of the Stern family, followed by a more technical section and, lastly, a detailed analysis of 38 dials of iconic 20^th-century models. Fréderic Burri, a former project manager at Stern Créations, took charge of the content and structure of the second part. Why did you choose to go with so much detail into the production and decoration of dials?

Dr. Helmut Crott: Like in art history, every period has its own manufacturing methods and specific indicators of style. Detailed knowledge of these sometimes minute differences enables you to judge whether a dial is in its original state, or if it has been badly restored or replaced. Take the Patek Philippe reference 1518 from 1940, [juste pour info, toutes les pages web que j’ai vues donnent 1941] for example. At that time, its dial was usually satin-finished, engraved and enamelled. But from the 1980s, the dials of this double complication perpetual calendar chronograph (reference 3970), tended to be sand-blasted. Once you know that, you can date a dial, even if anachronisms are frequently committed.

Here, we’re touching on the really unique thing about your book: it lays the foundations for visual knowledge of the dial as seen not from the perspective of the designer, but of the dial-maker. Through these hundreds of pages you build up a truly novel repertoire aimed at the collector.

During my long professional career I have been lucky enough to observe and evaluate thousands of wristwatches and pocket watches for auction houses and private collectors. I have gradually come to the conviction that in-depth knowledge of dial-making techniques helps distinguish the authentic from the fake. For example, you won’t find domed Breguet appliques in watches from the 1940s or 1950s. At the time, dial-makers followed the fashion of flat, polished appliques.

Another example: in a 1940 Rolex Prince model, I’d expect to find a grained, not a sand-blasted dial. I took my efforts to distinguish the authentic from the fake even further by creating a database of all the Patek Philippe watches sold worldwide since the 1960s. This mission turned into an obsession, devouring my holidays and weekends, because I didn’t content myself to listing the watches by market value, reference and movement number: I also painstakingly described and recorded all the available visual data.

Examples of codes engraved on the backs of dials manufactured by Stern Frères, then Stern Créations, from 1941 to 1985. Pages 128-129.

Helmut Crott

Was this titanic effort the origin of your book project?

Yes. My Patek Philippe database gave rise to the very idea for this book. From the very first weeks of working, I was forced to accept that I was also going to have to record all the available information about a dial: its exact colour, the type or types of decoration used, the finishes, the shape of the appliques, etc. – in short, everything I felt was crucial to identifying a watch.

Afterwards, the management of dial-makers Stern Frères entrusted to my company – TheSourceTechdata – the mission of indexing their archives, a unique legacy they wanted to safeguard at all costs. As the almost exclusive supplier to Patek Philippe from the 1900s to the 1960s, Stern Frères had a whole cache of remarkably detailed manufacturing documents. These listed not only all the finishes of a dial, but also the types of applique and additional parts. A real treasure trove.

Lastly, that gave me a better understanding of Stern’s economic choices. To give one example: the closure of the Enamelling department in 1957 prompted the management to develop new alternatives. It was against this background that Stern bought the former semi-precious dial workshops from Piaget in Lonay near Lausanne. It was there that Stern’s former technical director, René Baeriswyl, developed innovations such as the new ébauches in phosphor bronze, or how to drill through gemstones and ébauches using ultrasound. From 1981, this department gradually became part of the backbone of Stern Créations – which succeeded Stern Frères after the latter’s bankruptcy.

Dial prototypes by Stern Frères and Stern Créations.

Helmut Crott

Among other things, that mission put you in contact with several other managers at Stern Créations, who would be a source of key information for your book.

The initial project for the book dates back to 2007, more than ten years before its first edition. My exchanges with the former directors of Stern Frères and Stern Créations – André Colard, Roland Tille and René Baeriswyl, not to mention the project manager, Frédéric Burri – provided the basis for writing the book. During the three years preceding publication, I spent an average two to three days a week in Geneva, recording their testimonies. There was such a mass of information that I sometimes felt overwhelmed by the task.

Auction houses are sometimes faced with a formidable dilemma: whether to accept ‘as is’ a potentially interesting watch the dial of which has become worn over time, or to restore it. Are you in favour of systematic restoration? To what extent might this kind of “refreshing” devalue a watch?

I advise collectors to always think hard before deciding to restore. But, as I explain in my book, I see several levels of restoration. Whatever the case, a restored dial should never diverge from its original state. Restoration executed according to the rules, that is, in compliance with the dial’s original manufacturing methods, preserves the value of the watch. My own approach is first of all to analyse the state of the appliques. If restoration can be done without removing them from the dial, it shouldn’t result in any devaluation. On the other hand, if the dial is really too damaged, removing the appliques necessarily involves peeling off the Zapon (ed. note: protective coating) and consequently the transfer-printed numerals or hour, minute or seconds chapter rings as well. Only the use of plate cylinders from that period or extraordinary work on the part of the dial-maker can guarantee a high-quality result.

Recently, I contacted Cadraniers de Genève (ed. note: based in Meyrin, owned by François-Paul Journe) to restore a very valuable vintage Patek Philippe chronograph, because in my view they are the worthy successors to Stern Frères. Following my instructions, and after numerous exchanges, the team decided to process nearly fifty different plate cylinders to create a new tachymeter scale by transfer-printing. The final cost came to more than ten thousand francs, far higher than the initial estimate. Restoration is a highly intricate task which very few dial-makers are able to accomplish.

The different possible dial-finishing techniques: graining, horizontal satin-brushing, circular satin-brushing, sunray-brushing, sandblasting and/or mirror-finishing. Page 151.

Helmut Crott

The third chapter of your book unveils the manufacturing secrets of 38 iconic 20th-century models. Each watch dial, rigorously analysed and superbly documented, is shown to be hugely complex. What criteria did you apply to compose this list?

First and foremost, I wanted to illustrate all the manufacturing methods presented in the previous chapter. It’s rather as if I was inviting the reader to do some practical work after a lecture. Everyone can have fun guessing the techniques before reading my analysis. I was also set on giving an example of every historic singularity. Lastly, I felt it was my duty to choose the great watchmaking icons: the Rolex Daytona Paul Newman, the Patek Philippe Nautilus, the Audemars Piguet Royal Oak…

Above all, I wanted to decipher the world of dials by means of examples, images, but also by sharing the numerous technical complexities for which we all adore this extraordinary expression of the mechanical arts.