If this film is installed first surface inside a room, can people outside of the room see what is written on the film or is there complete opaque coverage from outside view

This particular Dry Erase film is the most opaque and would be the only one that hides what is written on the other side. If you look below the picture on the product page, you will see our statement as well. If there are any concerns, I would test some samples first just to be sure.