So I followed a banner ad from daring fireball and ended up making a shirt on redbubble. Basically it seems to be like CafePress, except targeted at graphic designers, and with those oh-so-popular American Apparel shirts and direct-to-garment printing. I didn’t have anything high enough res on this computer to make a decent print, so naturally I picked the lowest-resolution image I’ve ever made.
I actually bought one too, to evaluate the quality (as if this was a stressful test for their process!). If it’s nice, I’ll make more stuff. If not, I’ll go back to finding a real screenprinter to use. We’ll see!
(they also do prints on wall-board-like-material which is neat but I don’t anticipate using that just yet)