There has to be some material cats can use for indoor climbing
besides carpet or Sissel rope. Maybe something that also can be
attached to a 2 x 4. Maybe some sort of plastic grating (yes, of
course it will have to be safe). Next time I go to the hardware
store, I plan to spend a lot of time looking around. If I were able
to design it myself, maybe it would be plastic grating with 1/8"
holes deep enough so that claws would not hook into it. Besides cost,
the objective is to provide something which will last and won't
disintegrate. Any ideas for something besides carpet or Sissel rope
for cats to use for climbing? I suppose someday there will be a
material like sponge rubber which claws can dig into but not
penetrate.