Your acrylic is now ready to be covered with other layers. Before you stretch the Rosco on the acrylic you have to put a 1mm spacer on edges of the screen to avoid the Rosco being directly on the silicone rubber. I personally use arborite which is 1/32 inch thick. This small air gap helps to avoid the Rosco from sticking to the acrylic.
The easiest solution I find out to this problem its tape, I used the best tape I found. For the simplest result you start by stretching the center in both directions horizontally and vertically and then you process to the outside in rotation. Go by small steps to avoid wave in foil. First you have to stretch the Rosco than your protective foil. I use to cut both exactly the same dimensions of my screen so it simple to tape it on edges and at the backside.
As protective foil I personally use Insulating film which are really thin and retract when you blow warm air onto it. I took the thicker of the 3 size. You have to stretch it using the same method as the Rosco and then you blow warm air from an air dryer to eliminate waves. My results with this product were awesome compare to those obtain with my previous vinyl which was too thick and hard to hold with tape. I suggest you to put some layers of tape around the edges of the acrylic to help other tape to hold.
NEVER STICK TAPE DIRECTLY ONTO THE ACRYLIC OR COVER IT WITH BLACK PAINT!