I tie all my T-shirt quilts. I cut out a piece of felt that is 3" square and that is what I use as a spacing template. My shirts are 12" blocks and I put 2.5" (finished width) sashing between the blocks. I tie on the shirts only, every 3" and used polyester fat bat. I have used the perle cotton as well as 3 strands of embroidery floss. As all of mine were given away via a raffle I don't know how well they are holding up.