My DIL volunteered me to one of her friends who mentioned that she has all these T-Shirts from (I believe) her grandmother that passed away. I had never done a memory quilt, did not know the person I am making it for plus my DIL had these shirts in her car and had forgotten about them. The intended Birthday present was long gone.
The backing is the flat sheet of a Harley Davidson twin-size sheet set. Great because it still had a fitted sheet and a Pillowcase. Most of the shirts I could not use since they were heavily decorated with rhinestones. Well I did get it done and the quilt brought the owner to tears.
BTW After I had the squares assembled I found a small hole in one of them. So I took the tag from the back of a shirt and covered the hole with it. Looked a bit silly till I scattered a few more across the quilt.