Leather

Leather in watchmaking is not just one material: it's a vast family, and confusing one type with another is the quickest way to make the wrong choice. I've seen every possible variant pass across my counter, and the first distinction I always make is between full grain leather, surface-treated leather, and leather sourced from animals other than cattle.

Calf — calfskin — remains the standard reference. Soft, uniform, it takes dye well. When the surface is sanded and scraped on the outer side, you get nubuck: a velvety effect, pleasant to the touch, but more delicate in rain and abrasion. Suede is instead derived from the inner side of the hide: visually similar to nubuck, structurally different. Anyone using them interchangeably is making a mistake.

Shell Cordovan is a chapter of its own. It's not horsehide in the generic sense: it comes from the muscle membrane beneath the horse's hip, tanned for months — Horween in Chicago works it for months at a time. It's dense, doesn't bend with the same creases as calf, develops an almost metallic patina over time. It lasts decades if properly cared for.

Among embossed leathers, Epsom has a tight and regular grain, rigid enough to hold its shape. Saffiano has a crosshatch texture, resistant to scratches. Both are surfaces mechanically pressed onto a bovine base. Crocodile print and crocodile pattern embossing do the same on calf leather: they imitate reptile scales without using them.

True exotic leathers are another story. Alligator has symmetrical scales and a smooth surface; ostrich has the characteristic knots from feather follicles, nearly impossible to imitate convincingly. Goat leather is more textured and fibrous than calf, develops patina quickly. Deer — like the Flying Stag used by Oris — is incredibly soft and robust at once, with a sustainability profile tied to managed hunting.

There are also niche materials that appear on my counter with increasing frequency: salmon leather transformed by tanneries like Ictyos, with scale texture and natural iridescence, or sustainably certified leathers like Ecopell. These aren't marketing gimmicks: they hold up, they age, and some develop a patina that standard calf cannot reach.

The tannery matters as much as the leather itself. Tanneries Haas in France produce Baranil, hand-finished with sealed edges and linen stitching. Horween in the United States has standardized Shell Cordovan worldwide. The name of the tannery on a leather strap is not decoration: it's a guarantee of tanning, dyeing, and longevity over time.