I've done at least six t-shirt quilts. The last three were memorial quilts for a friend. I did an all over meandering large stipple on one, a large meandering swirl on the second, and flames (for the firefighter in the family) for the third. I used variegated thread and multi colored thread on them. I had no problem quilting over the top of the silk screening designs on the t-shirts. They all turned out beautiful.