Polyester felt that is sold by the yard...It is very wide and cheap. I line my stockings with muslin and put the felt in between both the front and back of the stocking...I only patchwork the front and use a solid or Christmas print for the back. When you do this, you do not have to quilt heavily just enough to hold all the pieces together. If you do the lining separately, just quilt the batting to the front and to the back if you are doing a binding all around the stocking, I would quilt all three pieces. This makes a nice firm stocking that can hold almost anything and will last for years. Well worth the time and effort. This type brings a nice price on Etsy and you will be proud of it. I have made about 10 this year and my family loves them. I also sometimes use warm and natural scraps...you can sew them together and then cut out the stocking.