Fixative for signature on fabric

[strawbrrysprite.livejournal.com]

Hello! Sorry this is text-only! I recently got one of my t-shirts signed in sharpie and I was wondering if anyone knew of any fixatives that would make it permenant?? I reeeeeeally dont' want it to wash out ^_^ I've heard that there are some floating around out there, but I don't know where to look!

Thank youuuuu!