CR[Moderator]
4018
Padding shape and variable thickness is also worth specifying.
I prefer padding that's thicker (maybe 3.8mm) near the watch head and gets thinner as you go down the strap towards the tail. That's functionally easier, too, if you use a tang buckle because you'll be bending the strap. It won't matter as much if you use a deployant buckle because you'll never bend the strap so acutely.
Also, you should be able to specify the padding profile (you can with JR, anyway). I like the padding profile to be softly rounded, like a semicircle, rather than have the more squared-off, vertical "drop" between the padded portion and the stitching that we typically see in today's Lange straps. The older Lange straps (made by Kaufmann, and also Perrin I think) had a more rounded profile. They were also slightly glossier, more semi-matte than totally matte.