I've made many t-shirt quilts and use Pellon 906F - it's almost sheer, and all you need is something to stabilize the shirt. MRSRAB, try to avoid quilting any areas with the heavy vinyl graphics - they just don't quilt well. I usually free-hand outline graphics, leaving them unquilted. Not quilting them also makes them puff out more, which looks great! I'm guessing that by the time it gets washed those holes may close up. If they don't, place it face-down on an applique sheet and apply some heat, which may help melt the graphic slightly and close up those holes. But do it carefully!