Cordovan

Cordovan is not leather in the common sense of the word. It is a fibrous, compact layer that sits beneath the hide on the hindquarters of the horse: two ovals per animal, roughly the size of two open palms. It is called shell because the tanning draws it out this way, dense and closed, without the grain that ordinary leather has. For this reason it has no grain to show: the surface is smooth, almost glassy, and catches light like nothing else.

The tanning is vegetable and long: a good six months between the vat, greasing and hand finishing, with the surface then roller-glazed until it becomes that deep sheet that is recognisable at a glance. Few in the world do it well: Horween in Chicago, who turned colour #8 — that dark burgundy — into a name of its own, and Shinki Hikaku in Japan, drier and more sinewy. The cost comes from this: two ovals per horse, half a year of work, high waste.

On the wrist it behaves in its own way. It is stiff the first few days, then settles and never goes back. It does not crack: where a calfskin forms a crease, cordovan forms a soft wave that is barely visible. With rain it marks — small pale bubbles that are alarming the first time — and a horsehair brush brings them back in. In twenty years of straps I have seen few truly wear out: they change colour, darken where the cuff strikes, and they last.

I cut it at 1.4 millimetres thick for flat straps, which is the right path for this material: padding takes away its character. It suits watches that carry a history — a Speedmaster, a Reverso, a 1960s chronograph — and dark or cream dials. It sits less well with polished steel than alligator; with satin finish and rose gold it is at home.

Little is needed to care for it, and that little must be done: a soft brush now and then, no greasy creams (they cloud it), no water on purpose. If it dulls, a cloth and the pressure of the hand bring the light back. It is a material that rewards those who leave it be.