This has been asked before, you can find the discussion here: http://www.www.opencarry.org/forums/...-Printing-quot
But, the consensus is that it's not breaking the law. I'm not sure that there's any "proof" cited though. Having said that, I like to wear tight T-shirts with my Glock 17 concealed in an OWB holster (i.e. it's much more covered than concealed) in anti-OC land. I've never been hassled, but that doesn't mean I won't ever be.