you can not use fabric as your fusable pressing sheet, people are thinking of two different things...i have one of the pressing sheets, it was expensive, it was required at a class i took i was not happy about being required to buy it, i force myself to use it because i have it but i think release paper works better.
if you always save the release paper from using paperback fusable you can then use that same paper to lay over your applique or you can see through it and use it over the pattern as a placement guide and build your applique on it after it cools you can peel the constucted piece off of it and adhere it to the background.
parchment paper will work too but for me it gets crisp fast, the release paper lasts better.