In its past Blancpain has created a number of iconic dial variations we
now have become appreciative of and allowed collectors a reason to chase.
Separated mainly into several categories including the early RI, 3/6/9/12, No
Radiation, and Milspecs. And within each category, there are numerous
variations, each with minimal differences in dial contrast. Rolex collectors
have long debated the reason behind Rolex's meaning of SWISS and Double SWISS
and for them it intertwines with the underline dial and year 1963. Although
there are no hard facts explaining exactly the reason but it is public
agreement that it was a transitional piece to signify the use or switchover to
Tritium.
Unfortunately, Blancpain has very little documented records and near
impossible to date. I have seen the same exact Double SWISS configuration on
both a 28xx serial and a 45xx serial case most recently and it is apparent that
case serials this far apart were not manufactured in the same year range. An
assumption is that Blancpain produced a number of a casebacks in the same era
beginning in the 14xx serial to early 5xxx serial with a number of dials and
variations and put them together not based on serials but what they had in
stock, hence we see these different variations in a sporadic range of serials.
Also, may help explain why we see some 3/6/9/12 have matte cases and some
polished.
So far I know of two different models of Double SWISS variation. One is
the Lower SWISS and the other is the Upper SWISS. The Lower SWISS has the
"SWISS" marking right underneath the 6 o'clock marker and the Upper
SWISS has the marking right above the 6 o'clock and beneath the moisture
indicator. In both models, they have another "SWISS" marking on the
lip of the dial.
In comparison to Rolex, we can conclude that for Blancpain it is
certainly not for the same reason as Rolex's use of Double SWISS. All of these
Milspec dials were still produced with radium even with the double marking. It
was not only until the No Radiation and later "civilian" Milspec
models where they began using Tritium dials. It will be interesting for those
who have a geiger counter to test out the radium levels of each dial. But even
with the dial changed to tritium, it is not to fool collectors that the watch
is radioactive free. The bezel still is radium strong!
This is an example of a Milspec dial you normally see on early Milspec variations.
Above is the second variation of the SWISS word placement. Visually, you can see the difference where SWISS is inside the chapter ring and right beneath the 6 o'clock marker. There is also another SWISS wording on the outside of the chapter ring, which is hidden by the rehaut.
Here is a better picture to demonstrate the Double Lower SWISS dial configuration. Because the outside SWISS wording is right on the rim of the dial, it is most often covered up when on the watch.
The last configuration I have come across is the Upper SWISS configuration. Also not often seen, the wording is placed right above the 6 o'clock marker and beneath the moisture indicator.
Finally at the end of the radium dial Milspec production, it is noted that dials were switched from radium to tritium dials. All "civilian" Milspecs are seen with this variation and with some early Fifty Fathoms containing this dial. Questionably, I wonder if those are original to the watch. Anyways, it is apparent that the later dials had a smaller circumference chapter ring along with "T<25" marked on the dial, signifying the use of tritium.
Of course, there still remains many other anomalies even just with the Milspec variation, but these are the ones I have noticed with the SWISS marking.