Leather is available in different kind of types, like full-grain leather. It breathes and is as natural as possible. Nubuck is a top-grain leather with a surface that feels like velvet. Shell Cordovan is durable, almost self-lubricating and gains a fabulous patina. Suede is what you get after you have taken the top layer of the skin. And then you have lamb skin that is well suited for bags and watch straps. The Swiss company Rhein Fils knows how to make leather watch straps. It started in 1913 in Saint Imier and it does still exactly what it started out to do: design and manufacture leather products in a traditional way.