We have two leather couches (some might say one for each of our cats...). Like me, they love to lay on them because they're soft and warm, but they've NEVER intentionally clawed them. Our youngest, Chloe, has left a few scratches because she'll spaz out if the doorbell rings, but the cats don't scratch on purpose. As long as you have something else they can scratch (our cats love those cardboard scratch things) I'd think youd be OK with just about anything. To be on the safe side, though, I'd stay away from anything with loose threads. If you keep their claws trimmed, their kneading shouldn't hurt leather or fabric. The other nice thing about leather is that it is easy to clean - stuff (read: cat hair, cat drool, maybe even cat puke, though we haven't had to deal with that yet....) pretty much wipes off.