These are brilliant! And may have given me an excellent idea for holiday gifts (I'm allergic to cats, but lov'em, so I live vicariously through my siblings and friends).
Question: What would you suggest for materials that can stand up to mauling by cats?
I used a stretchy wool blend I found in the remnants section. I wouldn't use anything like cotton or any kind of quilting material. They'd easily tear through that with those hooks! I'd suggest a medium-heavy material or even wool felt would work.