Shaped watches are a key feature of Cartier. Some models like the Tank Française are defined by their hard, sharp edges, while others such as the Ballon Bleu de Cartier are comprised entirely of soft, sensual curves. Most timepieces from the maison will fall somewhere in the middle of the spectrum, of course. The Santos de Cartier, for instance, sports straight edges that are softened by rounded corners, while the Crash completely defies any sort of categorisation with its irregular outline.

The challenges involved in creating a shaped timepiece are aplenty, but Cartier routinely overcomes them all. For a start, there is the obstacle regarding internal space for the movement – while a squarish case can still accommodate a regular round movement, an oblong- or oval-shaped one is a far more difficult fit. Cartier’s solution has been to work within these constraints by engineering matching shaped movements. The Tank Asymétrique, Crash Skeleton, and Tank Cintrée are just some prime examples of these. The Tank Cintrée’s custom calibre is especially amazing – it is curved along its longest axis to match the internal space of the watch case, which necessitates three-dimensional displacements of various components. With such ingenious watches, the maison doesn’t just show off its eye for design, but also its expertise with movement development.

A shaped timepiece also presents hurdles in the form of aesthetics. Round watches are obviously easier to design since it’s less troublesome to get their proportions right. Square, tonneau, and other such shapes, in contrast, demand a keener eye and a defter touch. How does one keep the hands on a rectangular watch legible at six and 12 o’clock, while ensuring that they don’t look out of place at three and nine o’clock, when they are aligned to the dial’s shortest axis? How would an elongated watch sit comfortably on the wrist? How do the indices fit on the dial?

The last major challenge for shaped watches lies in its very production. Machining the case of one requires considerably more planning and potentially more material wastage, for instance, and this extends to other components like the sapphire crystal, which may need complex curves to fit its case. Elsewhere, screws of different lengths may be needed at different spots on the case back, which further complicates the assembly process.

A look at the various shaped timepieces that Cartier has created, however, is a reminder that it is all worth it. Some, like the different iterations of the Tank, are variations on a theme. Others like the Drive de Cartier are wholly original, and well on their way to become icons themselves.