Earl,
The sandwich goes like this....bottom layer tissue cloth
middle layer plywood
top layer 0.75 oz cloth
We use the West System epoxy to wet out the cloth.
when vacuum bagging it we put that sandwich between mylar sheets, ring that whole assembly with paper towels for breathing cloth and then close the bag and apply vacuum.
The vacuum compresses the mylar against the deck and squeezes out the extra epoxy and also gives the deck a smooth surface, as long as you haven't trapped any air bubbles between the mylar and the deck. Its important to get out any air pockets.
Ken S