Continuing the discussion from Engraved Leather:
Trying to understand nomenclature here: is it presumed that oil tanned leather is different from chromium tanned leather is different from vegetable tanned leather?
Can you have oil treated but vegetable tanned leather and also oil treated and vegetable tanned leather?
Earlier discussion on oil tanned leather indicated that it was a mess. @Andy_Mock’s stuff looks fantastic!
The tanning process is quite complex but you can find hybrids of the ones you mention above. The pictures of my remnants are a mixture of all 3.
The oil gives it a distressed look, Chromium is sometimes required in the process to import hides and it allows the dying process to occur much faster.
In certain processes oil and vegetable tanning can be interchangeable, or the same although in this case it probably refers to the distressed finish I mentioned above.
I would disagree you can’t laser chrome tanned hides as this is what most large manufacturers use but the fumes need to be controlled.
Thanks. I didn’t recall the oil part of that discussion and missed it in the search, just had remembered the original discussion that oil was messy. Glad other folks are doing all this testing and figuring this out.
I’m moving this to “beyond the manual” as people are discussion processes that may be hazardous.
As I recall his post, he cut the leather using a steel tool and used the 
for the engrave. For leather there is the tanning process and then they may dye it as well. So many variables, so many secret recipes, I think you just need a small scrap and try it. Everything I’ve read about not burning a chromium tanned hide originates from Indian villages where the inhabitants are burning the scraps as fuel for cooking fires. I intended to at least try some non-veg tanned leather. I am not recommending anyone else try it, but to me the amounts burned away, and then vented away, by the glowforge are an acceptable health hazard.
Yes. As @exponissi pointed out, it is possible to have hybrid tans. @morganstanfield offered a nice overview in this post.