Is it appliqué with a lot of different pieces that you make into one large appliqué before pressing it to the background fabric? If so you need a Teflon pressing sheet. This allows you to peel the backing off all your pieces, layer, overlap and fuse them together on the sheet. The whole appliqué will then peel off the sheet ready to go. I don't know any other method for doing this.
If it is a pressing sheet for going over the top of appliqué when you iron it down, could you use tin foil? I would try a sample first before trying it on my actual appliqué. I usually just iron my fusible appliqué down to the background without anything on top.