The designs on t-shirts used in memorial quilts are often already showing signs of wear and I would never want to do anything to hasten the deterioration, so I never sew across the design when quilting a t-shirt quilt. I’ve seen plenty of t-shirt quilts with overall, edge-to-edge quilting and I worry about the print peeling or flaking away from the fabric, especially if the quilt is used often and washed regularly.
Outline quilting is best done free motion so the fabric doesn’t shift while stitching. Here are shots of the front and back of an outline-quilted section.
Note the breaks in the outline quilting where the dolphin fins and tails crossed the waves. Although it takes more time to tie off and bury the thread ends, I think it’s worth it to ensure that the t-shirt design isn’t punctured by the needle.