I was time this morning to give it a go. I went in search of an old t-shirt to use since this is an experiment. I found one of Wyatt's little shirts he outgrew and gave it a go.
First cut off the design leaving plenty of room. This one is closer than I wanted but it was a tiny T-shirt so it was a small design.
This is Heat and Bond. You buy it on a roll at Walmart or any place you buy fabric.
Heat and bond has two different sides.... the one side has a shiny look to it and that is what you use to bond it to the shirt.
The other side will simply look like paper.
Cut a piece of the Heat and Bond just smaller than the design. This is IMPORTANT! That glue stuff gets hot and it doesn't care what it bonds to... it will bond to your ironing board cover or your iron. If you feel you must have the Heat and Bond hanging off the design I would use a pressing cloth that you don't want anymore. Make sure your iron is HOT. The turn your design facing down then lay the glue side down, leaving the paper facing up. Press and iron all over the paper so it will stick to your shirt. Set it aside and let it cool.
Now this is the part that makes it stable to sew with. Pick a fabric that you will use behind your blocks, cutting it larger than the design. In the end it will not be seen but if you are doing a white T-shirt you don't want black backing. Press the backing fabric.
The Heat and Bond will have cooled now. The paper peels off like this. The glue is now on the t-shirt. Sorry you can't really tell in the picture. Peel it completely off and throw away.
Lay your T-shirt design down then put your back fabric on top and press in the same manner as before.
When you are done it will look like this and will be stable to sew. There is no stretching now. Cut your design to whatever size you want and make your quilt.
