Friday, April 18, 2014

The Complete History Of the "California Dial"

...California Dreaming...

The Complete History Of The

 "California Dial"

Rolex Myth Buster

On The Curious Case Of The California Dial

This article will dispell two false myths regarding the so called "Califorinia Dial". The first myth suggested the California dial was used in a Panerai Prototype in 1936. This is comletely untrue, and you can learn why by visiting  

Rolex used to make watches with Art-Deco styled dials that were really distinct. These dials featured an upside down triangle for the 12 indices, and rectangular indices at 3, 6, and 9. The 1, 2, 10 & 11 markers used Roman numerals, and the 4, 5, 7, and 8 markers used Arabic numerals.

For years, people have referred to these unusual dials as "California dials" and people ask me all the time why the California Dial is called, "The California Dial." In other words, what does it have to do with California? The photo below was taken by Harsam of his 1943 Rolex Bubbleback, which has an original Art Deco "California" dial.

The photo below shows a beautiful Rolex Art-Deco poster which features a "California Dial" with Radium Innovation. Radium was the first type of luminescent material used to make dials glow in the dark.

In the photo below we see another two Rolex Art-Deco bubble-backs, and the one on the left has a white California dial.

Rolex "Bubble-Back" models are called this, because Rolex used to try and make watch cases look as thin as possible to try to hide the large, rounded case backs which concealed the large automatic winding rotor, and they achieved this by giving the watches convexed backs, which made them sit up proud on the wrist. 

Today, most Rolex watches have completely flat-backs, which I would argue make them lay flatter and fit better on the wrist.

1942 World War II 
Rolex U.S.A. Christmas Message

The Rolex Christmas ad seen below was published in the United States in 1942, and if you look closely you will see a "California Dial" Rolex in the center of the row of Rolex watches at the bottom of the ad.

1942 World War II 
French Rolex Ads 

1943 Swiss Magazine Ad
Rolex Bubbleback

The image below is from a Swiss magazine that was published in 1943 and it shows a beautiful Rolex Bubbleback with a classic California dial, with Lake Geneva shown in the background. This watch was a harbinger for the magnificent art-deco design language that would evolve a decade later into the Submariner and GMT-MASTER.

Pictured below, we see yet another Rolex Advertisement which is from 1945.

The Rolex magazine ad pictured above reads:


The figures and divisional signs are deeply recessed and filled with stong luminous compound.

Fully winds itself automatically and silently by 6 hours normal wear on the wrist. If wanted it can also be wound by hand in case of illness. No shocks nor vibration disturb its precision. Superlative finish of every detail. In addition to constant and even tension of mainspring-power, contribute and facilitate the obtaining of almost unbelievable regularity in precision timekeeping. Every one of these self-winding chronometer wrist-watches is now supplied exclusively with a Swiss Official Timing certificate and impartial document of quality and highest precision. Montres Rolex

Below is a similar 1945 Rolex ad, but this one is in Spanish:

Panerai "California" Dial
In the entire course of history, Rolex never made any watches for any brand in the world, with one exception, and this was for an Italian manufacture named Panerai. The vintage Panerai watches were never made available to the public because Panerai made them at the time exclusively for the Royal Italian Navy. These special watches were a military secret at the time.

There was a persistent myth that suggested the very first Panerai production models, which were made between 1936 and 1938 featured the Art-Decom masterpiece "California" Dial as seen in the photo below. This is NOT TRUE. These watches were actually made in 1944.

The Rolex made Reference 3646 pictured below is a highly collectible watch today, and it is unusual in the sense it has no brand designation on the dial. 

Not only was this the first Rolex made diving watch in history, but it also was the basis of what would go on to become the most iconic watch ever made in history, which was the Rolex Submariner. You can always learn more about the Rolex/Panerai connection on Jake's Panerai World.

The "California" Dial Nomenclature

Rolex Patent Application

June 15, 1942

Rolex applied for a patent for this special dial on May 30, 1941, and the patent was granted on June 15, 1942, as seen in the patent application below. So where id the name, "California Dial" come from? 

The patent application pictured above, when translated from French to English says:

The object of the present invention is a timepiece dial. This dial is characterized in that it comprises hourly signs constituted by Roman numerals and others by Arabic numerals. 

The accompanying drawing shows, by way of example, four embodiments of the object of the present invention. 

FIG. 1 is a plane of the first embodiment. Figs. 2, 3 and 4 are small-scale planes, the second, respectively the third and fourth embodiments. 

The dial of FIG. 1 is a round dial with an hour circle with twelve signs, one for each hour. The signs for hours 10 and 11 and 1 and 2 are Roman numerals, those for hours 4 and 5 and 7 and 8 by Arabic numerals and those corresponding to noon6 o'clock3 o'clock and 9 o'clock, By simple geometrical elements, namely a triangle and three horizontal sticks.

It will be seen that this layout gives a clear and simple turn of the hours, easy to realize with luminous material and allowing an easy reading of the time especially for wristwatch boxes whose dials are relatively small. In fact, the fact that the Roman numerals occupy half the dial and the Arabic numerals the other, clearly distinguishes these two halves. In addition, the Roman numerals chosen are those which are the simplest to perform and the easiest to read.

In the other three embodiments, the hourly sign corresponding to time 5 is constituted by the corresponding Roman numeral and the hourly sign corresponding to 6 hours is constituted by a very short vertical line. In the embodiment of FIG. 2, the sign corresponding to noon, is indicated by a vertical line, in that of fig. 3, by two vertical lines and, in that of FIG. 4, by a short stroke surmounted by a half-circumference. Of course, the aforementioned provisions could be applied to dials of a shape other than round and other arrangements would still be possible


Dial of timepiece, characterized in that it comprises hourly signs co-located by roman numerals and others by arabic numerals. 


1. Dial according to claim 1, characterized in that it comprises: In addition, time symbols constituted by triangular geometrical elements.
2. The dial as claimed in claim 1, wherein the symbols corresponding to the hours 10 and 11 and 1 and 2 are constituted by Roman numerals.
3. Dial according to claim 4, characterized in that the signs corresponding to Hours 4, 7 and 8 are Arabic signs.
4. Dial according to claims 1 to 3, characterized in that the corresponding 5-hour sign is the corresponding Roman numeral.
5. Dial according to claim 1, characterized in that the remaining digits are constituted by geometrical elements.
6. Dial according to claims 1 to 3, characterized in that the sign corresponding to 5 hours is constituted by the corresponding Arabic numeral.
7. Dial according to claim 6, characterized in that the remaining signs are constituted by the geometric elements.

MONTRES ROLEX S. A. Mandataire A. BUGNION, Genève.

1941 Art-Deco Rolex Viceroy

This is a World War II circa Rolex Viceroy with an Art-Deco California Dial. The California dial has Roman numerals on the top and Arabic numerals on the bottom.

Photo Credit: Padi56

The "Semi-California" Dial

So where exactly did the Rolex "California Dial" design come from? Nobody knows for certain, but we can study the history of the design language. 

The Semi-California (seen above and below) has the upside-down triangle at 12 o'clock, coupled with the triangle markers at 3, 6, and 9, along with the 1, 2, 4, 5, 7, 8, 10 and 11 markers in Arabic. 

Adam took the photo below of three Rolex Speedking bubble-back models that were made between 1944 and 1945, and on the far left we see an model with a standard Arabic numeral dial, next we see what is commonly referred to in Rolex collector parlance as the Rolex "Semi-California Dial."  Then on the far right we see a standard California Dial with the Roman Numerals on the top with Arabic Numerals on the bottom.

When carefully studying the visual differences between the three Rolex SpeedKing models pictured above, I could not help but notice that the "California Dial" version on the right is the most stylized, and it is the only one with the closed "train track" chapter ring that runs around the outer perimeter of the dial, and it is also the only one with the blued and highly stylized hands which include the "Mercedes" logo on the hour hand, coupled with the hour hand that has a pyramid on the end. In other words, the California dial version has the boldest Art-Deco style details, which make it really pop!

Update #1

A reader named Tommy wrote in response to this and said:


I think the "California" dial may have it's origins with the Melrose Avenue shops in L.A.

The dials became very popular during the bubbleback craze of the 80's.  Many of the refinished dials being done for watches that these shops sold were half-and-half dials because they were so "deco" and were so popular with the people buying bubblebacks. 

I think L.A. dealers were seeking those dials ON bubblebacks that they were buying and selling in their shops and so they became known as "California" dials because the California dealers were looking for them at shows elsewhere in the country.  The people at the shows began referring to them as "California" because it's what the guys from California were looking for.

All is speculation but of course the term is only showing after the 80's.

The dial is really a half-Roman and half-Arabic dial, and that is how I have always referred to it. I never liked the term "California" because it was really irrelevant.

Another interesting variant is the all arabic with the triangle 12 marker. This is often referred to as...of all things  "semi California".



Update #2

I came across somebody who quoted James Dowling as saying:

"The dial was patented by Rolex in 1941 and used by them on manual and automatic watches for about 7 or 8 years. It was known by Rolex as the 'High visibility" dial, as it used quite large luminous numbers. 

In the 1970s, when the vintage watch boom started, a LA based dial refinisher, Kirk Rich, did some dials with this design. They became popular & many vintage watch stores in California sent their dials to KR. So dealers in the rest of the US & the rest of the world began to call them the 'California' dial."

Update #3

I came across somebody who said:

Rolex created the “Cali Dial” for it's various distributors and it became a fashion icon of high demand in California in the 30's-40's – hence the name.