Songbird,
I am using molds for my cards but I am not selling the molds or designs. Just what I make from them.
Copyrights. Creative Cash by Brabec may help you and I believe she has a website. I would type in Creative Cash or brabec.
The library is a good place to find the information about copyrights or a bookstore. I've been looking for a book I had that had papers like that in it but of course I can't find it when I want it. This book I believe was written by artists for artists.
Maggie