Donna, I have done many tee shirt quilts and I always quilt on top of the shirts. I tend to quilt each shirt differently, but you could do the same design on all of them. Here is a couple pics to show you what I mean.

I usually trace around larger elements on the tees rather than punching through the silk screens, but you can if you stay on lines or color changes in the design so its not obvious.Hope I helped :-)

char

Thanks, Char! I like your quilting. I think I’ll end up doing a mixture of designs.

I have made several of them. I SID around the shirt, do a meander in the background and switch to thread that matches the tee shirt to accent the design on the shirt. If the piece of the tee shirt isn't large, I don't quilt on it.

Do you quilt in the "shadow"?

Sometimes, but try to do it in a color that matches the shadow (usually black, sometimes gray). Sometimes I just SID around the shadow.