I've made several t-shirt quilts and have used "french fuse tricot" to stabilize. It's lightweight and doesn't cause problems with the quilting. If you can find the 60" width it makes it a lot more economical. A couple things; it has two directions, one that stretches and one that does not, so you need to make sure the "stretchiest" part of the t-shirt doesn't have the stretchy part of the fusible; also you need to use some kind of pressing cloth when ironing it on.