For the first time, the 41 mm case and bracelet of the Royal Oak Perpetual Calendar are entirely honed from blue ceramic. A light material resistant to wear and scratches, ceramic accentuates the slenderness of this timepiece measuring 9.5 mm in thickness. Ceramic requires precise manufacturing and meticulous hand-decorations to respond to the Manufacture’s high quality requirements. Zirconium Oxide (ZrO2) powder, modified to obtain a blue pigmentation once baked, is mixed with dedicated binder content before being transformed into ceramic through a complex industrial flow requiring different stages of high-precision machining. The exact composition of ceramic remains the secret of its manufacturers. The components achieve their final colour only once they have been sintered at more than 1,400°C. Reaching a homogeneous colour represents an additional challenge as ceramic’s final colour depends on the sintering temperature, which allows no variation.
The Le Brassus artisans have finished each ceramic component with the same detailed and meticulous hand-finishes as they would if they were honed from precious metals: the Manufacture’s trademark alternation of satin-brushing and polished chamfers has been applied by hand with extreme care, resulting in a rich play of light which enhances both the ceramic and the multifaceted architecture of the Royal Oak.
The Manufacture’s artisans have harmonised the blue-toned colours of the Grande Tapisserie dial, subdials and inner bezel, obtained by Physical Vapour Deposition (PVD), to the blue ceramic case and bracelet, conferring the Royal Oak Perpetual Calendar a contemporary monochromatic aesthetic. The 18-carat white gold applied hour-markers and facetted hands, filled with luminescent coating for optimum visibility in the dark, provide a bright contrast. With its three calendar subdials and moon phase aperture equally distributed on the dial, the watch presents a fine aesthetic balance, while granting optimum legibility of the hours, minutes, day, date, week, month, astronomical moon and leap year indication.
This new model is equipped with the selfwinding Calibre 5134, which testifies to the Manufacture’s savoir-faire in terms of classic complications. This mechanism automatically takes into account the number of days in the month and correctly displays the prevailing date even in leap years. Assuming the watch is kept regularly wound, the date will not require manual adjustment until 2100 to stay in line with the Gregorian calendar.
Launched in 2015, this movement measuring just 4.3 mm in thickness necessitated the re-arrangement of numerous components, including its 22-carat gold openworked oscillating weight. The bulkiest part of the rotor has been positioned to its outer edge which is recessed within a channel encircling the movement, thereby mitigating height. Likewise, the choice of a suspended barrel has contributed to reducing the movement’s thickness.