Maybe you could use a sheet of waxed paper or some thin plastic sheet just like the Pocket Duct product. I have also had problems with the heat. Always try to obtain the quality stuff.
Try going to a sign shop that does vinyl lettering for banners and ask for the scrap backing for the vinyl. The stuff comes in large sheets.
Try going to a sign shop that does vinyl lettering for banners and ask for the scrap backing for the vinyl. The stuff comes in large sheets.