I prefer leather and Tosca couldn't care less. It doesn't matter what collar I put on her, it disappears in her fur, she doesn't seem to mind leather or nylon, so I have both. She has two leather leashes, one if a nice handmade Latigo I got at Lucy's, one of our Chaz member's sites. I prefer leather leashes, I just like the feel and look of them. If Tosca's collar would show, they would all be leather.