Tooling question

[Abominable Bill]

How do they add tooling to the rough out side of leather?
I see a lot of saddles with rough out seats and fenders with some tooling on them.
How do they do that?
I have a hankering to make a pair of rough out holsters but am wondering how I would add border tooling

[ChuckBurrows]

Tandy/LF sells a book by Al Stohlman on the process or a least they used to........

[Marshal Will Wingam]

I've done rough-out tooling before. You cut the pattern with a swivel knife first. Then you inside bevel the design and use a background tool like an A104 to compress the grain between the cuts. There's no detail work to do though. It's pretty much a solid stamping.