I made one a few years ago for my son from his many Harley Davidson shirts..and I used the book, "TOO COOL TSHIRT QUILTS"
It was a really good book with good instructions. The site is www.toocooltshirtquilts.com
they give instructions for many sizes….I went to Lowes and had them cut plexiglass for the templates….
it took awhile but I was in no hurry…….
and the final project was loved by my son….and that make it all worth while
yes, you must use a fusible interfacing. good luck.