I purchased a package of iron on nylon tricot interfacing from Nancy's for $22.95. It was 60inches by 5 yards. I cut it into 1.5 inch strips and wrapped the strips on a round cardboard core (about 4 inch diameter). Obviously, the cost was very small compared to purchasing the prepackaged. It took me about an hour to do this. I save my batting scraps that I square up when I cut them off a project and mark the size on them. I have been making quilted items for a community boutique craft sale and have used most all of my scraps of batting. Feels great to lighten the storage load.