I used the lightest weight non-woven interfacing to stabilize the t-shirts, poly batting and flannelette backing. My first one for my daughter lasted 10 years till the crests were worn off the shirting. The flannel back is smooth as silk. It has been their go-to quilt if they wanted to get warm or were felling terrible. It was well-loved and still holding together. We're going to make a new front from her dad's t-shirts and add new backing and use the old quilt as batt.