I've found that it varies from shirt to shirt, design to design. It's not consistent, depending on the colours they offer, etc. As for the screen printing on the shirt, can't really say without seeing a photo, but if you're talking about this one:
http://s100.photobucket.com/user/dec...jvaui.jpg.html
...I think it might be intentional as it's supposed to look retro like it's a worn shirt from the 80's (which also might explain their choice of a thinner shirt material as old 70's and 80's tees were typically thin and fitted).
