Has anyone made polymer clay kitchen cabinet knobs? If so, how do they wear and do you like?

The clay will wear and can form dents especially if you use a soft clay like Sculpey. I'd suggest Cernit, or Promat, or CFC brand so it will stand up to wear better. Otherwise making cabinet knobs is a great use for polymer clay. Here are some knob examples and instructions from the Sculpey website:

http://www.sculpey.com/Projects/projects_Knobs.htm