Agreeing with this. Also to get a variety of leathers people use. I mean in my opinion at the end people use mostly sturdy-patched ones with either fortitude, negative energy or hide bonus. Maybe something different could be thought, according to different materials.
Plus, it's some time I haven't crafted leathers since I've reached a good level, no one asks me for them, so simply stopped. This is why I don't remember actually the kind of skins, but I could not help noticing there are some leathers which, combined, give a final result which is basically the same, but the DC varies consistently. And maybe I'm the only one pondering about this: bodaks are very high DC but the result is NOT that useful...