Do fabrics have copyrights?

if you want to use a fabric for resale do you need permission for the designer. I'm mostly talking about online fabric stores but would like a little insight about retail stores too would be nice. And as far as patterns go, if you use a pattern but modify it in a few different ways, is it considered your own original that you can sell under your name? I'm talking a babywear item that is popularly remade and sold by many different sellers. Thanks!