I agree with Sully. When you make a pattern, according to copyright law, you own the copyright to it. If you want to go all official, you can pay to have it trademarked. It's really douchey of someone to turn around and sell your creative material that you shared online for free.
The cuttings themselves fall under works of art in a subset of copyright law. Some companies (Disney, Marvel, etc.) will send cease and desist (and sometimes go as far as suing), over selling items or patterns made with their trademarked characters. Sometimes they win, sometimes they not because of the works of art law, but it's not worth the court fees to find out. There are way too many open domain options out there.