Cartier Baignoire Mini Model Diamond Bezel 18 kt White Gold Ladies Watch WB520027

WORLDTEMPUS - 27 January 2012
So what is the answer to this question? Is thin still in? During last year's SIHH, thin cases and movements underscored the return of watchmaking to a more sober, creative style where classically simple timepieces only displaying the hours and minutes made headlines in the specialized watch media. So thin watches were definitely "in" in 2011 and they definitely held their status for 2012. Most watch brands at this year's SIHH presented at least one piece we can file in the "thin" category, with others pushing the envelope a little bit further toward the "extra-thin" level, depending of course on the number of additional complications or indications contributing to the overall thickness of the movement and, consequently, to the case itself.
So let's start with the thinnest of all presented this year at the SIHH, which necessarily only includes watches showing hours and minutes - and no more. The classic Cartier Tank XL slim line made good use of Caliber 430MC, a movement that is in fact the incredible Piaget 430P used in the Altiplano and Dancer lines. The movement's remarkable thinness of just 2.1 mm allowed the Cartier Tank XL to also claim a height of just 5.1 mm for the case. Second in line was the Van Cleef & Arpels Pierre Arpels watch, a reinterpreted model of the Parisian house originally launched in the 1940s. Using Piaget Caliber 830P, which is only 2.5 mm in height, the new Pierre Arpels is now a serious contender for supreme elegance.

With a movement just 2.8 mm in height, Vacheron Constantin made use of its Caliber 4400 to present the new Malte 100th Anniversary in platinum, a tonneau-shaped timepiece commemorating the centenary of the brand's first shaped watch. 

Only one-tenth of a millimeter thicker than the Vacheron Constantin, manually wound Caliber L093.1 from German manufacture A. Lange & Söhne powers the new Saxonia Thin. A watch chock-full of Glashutte's inimitable art of watchmaking, fully wound it guarantees a power reserve of no less than 72 hours. Last in this category of ultra-thin watches only showing hours and minutes is the Audemars Piguet Royal Oak Extra Thin, launched in the year this historical line turns 40. Although it has an additional date window at 3 o'clock and a self-winding rotor, AP's in-house Caliber 2121 is just 3.05 mm in height.

Slim skeletons and tourbillons
Working the diminutive plates and bridges of a conventional mechanical wristwatch movement is already demanding enough work for any watchmaker. Performing this work on an ultra-thin movement is something only a very few haute horlogerie brands are able to do. Already considered a master in the domain of ultra-thin movements, Piaget has outdone itself by skeletonizing Caliber 1208P (2.35 mm in height) and giving birth to the new 1200S caliber by adding just 0.05 mm height. This is a remarkable technical achievement whose relevance directly competes with the modern and attractive overall image of the Altiplano models.

The second new product to combine ultra-thin mechanical movements and the art of skeletonization at the SIHH was the Jaeger-LeCoultre Grand Reverso Ultra-Thin SQ. Making use of Caliber 849RSQ with a record-breaking 1.85 mm height and 128 parts, just considering the difficulty of making this movement into a skeletonized structure is mind-boggling and in itself an impressive accomplishment. Jaeger-LeCoultre rightfully called it a "steel labyrinth with two finely crafted faces."

On to another category of ultra-thin timepieces presented at the 2012 SIHH: watches with small seconds were well represented by the Parmigiani Tonda 150 Special Edition, a model that has clean lines, a fine profile and excellent proportions. Caliber PF701, which powers this wristwatch, is only 2.6 mm in height, even though it is an automatic movement equipped with a micro rotor. This is impressive since the only other ultra-thin watch presented this year in Geneva was the manually wound Malte Small Seconds by Vacheron Constantin. Its Caliber 4400AS is 2.8 mm in height, a full two-tenths of a millimeter thicker than the Parmigiani caliber. 
Before moving on to the most complicated category of thin watches, one would be remiss in omitting the Jaeger-LeCoultre Master Ultra-Thin Reserve de Marche. Though it has a central automatic rotor, it also displays hours, minutes, small seconds, date and even its power reserve. With all these indications, the 273 parts of Caliber 938 do not exceed 4.9 mm in height.
The most complicated category of ultra-thin watches is the one where a tourbillon makes its mark, and only two brands dared to compete this year in this field. Audemars Piguet presented the beautiful Openworked Royal Oak Extra Thin Tourbillon 40th anniversary edition, along with another non-skeletonized version. Both models utilize hand-wound Caliber 2924 with a remarkable height of just 4.46 mm.
Finally, and at 6.4 mm, Caliber 899 of the Jaeger-LeCoultre Ultra-Thin Tourbillon is 1.94 mm thicker than the Audemars Piguet. Its extra height can be attributed to the central rotor added to its mechanical structure. However, in this category the king's crown still belongs to the exceptional Piaget Emperor Coussin Automatic Ultra-Thin model presented at last year's SIHH. Its Caliber 1270P remains the thinnest tourbillon movement equipped with a micro-rotor in the world: it is only 5.55 mm in height.