I use Insul-brite in the center and cotton batting on either side. I just layer and quilt through it all, then bind. Mine have been washed many times and although these is some shrinkage, they still look fine.
My guild has a potholder project there they collect them all year and sell them in a booth at our quilt show. The money goes to our service projects. They provide the Insulbrite and suggest this method. I make a lot of my leftovers into potholders.