If you copy a quilt exactly like a copyrighted pattern then it's not your design. If you start with the basic design and change it enough to look like another design then it's yours. I see so many 'new' patterns out now that are nothing but copies of other patterns and they are selling with no problem. I don't copy or sell copies of bought patterns or claim the design as my own as that is the law. The rest are just rules put on the pattern by the designer or publisher.