Tom, you can get the sound you're looking for from potato chip bags (crisp bags that have been opened at both ends then split up one side and wiped off very well). When these are placed in a quilt the quilt can still be washed and dried (only not on high heat). When I make mine I use two bags (medium sized), for more sound. I also try to put in the large toothed zippers (plastic), because they are heavy duty and have a good sized tab for opening and closing. I did a special order one that had a pocket in it, then I put two hankies sewn together and then sewn into the pocket on one side (this way the pocket can be opened and something comes out and then gets put back). My clients mother loves her pocket, she will pull the hankies in and out all day. Anything you put into your quilt, needs to be washer and dryer friendly. Because these quilts are in and out of the machines a lot. Good luck