@QuizBasenji:
The sofa Butu and Leki are pictured on is leather. Apart from Butu doing the soft shoe shuffle on it before he settles down, he has never tried to hurt it. Leki seems to be unravelling a couple of threads in its bowels, but that should stop when she's too big to get under it… Butu has eaten three computer chairs, so I was very loath to get a leather sofa, but now I would have all leather furniture if I could!
I view it the same way. I was hesitant dropping money on a new sofa, leather especially. Found out that it holds up far better. Easier to clean, and they really seem to have zero interest in chewing on leather. Anything fabric (like his blanket) will get damaged one way or another.
Leather seems like the way to go. I've never seen Kananga attempt to dig on the leather itself, only when he's standing on his blanket. He'll attempt to dig on my bed, which is rather frustrating (as bed sheets don't hold up well over time).