stuffed cotton pleates. Thanks for the replys. John no offense or disrespect I love your channel. You do great work on it. And I agree there are many ways and techniques. I just think the bottom should be taunt, especially a one piece bench seat cover. I like tight fitting cover. I don't see where the Muslim would shrink. It may look like it did but if you pull it tight from side to side, you should get the length you had when you start. That being said for stuffing pleates. I do allow for shrinkage on top stitch pleating when doing todays style with sew foam. I allow 1/8"per pleate.