@animeman0 there’s too many variables to give you an answer as it depends on there following: is there an angle difference between the monitor and glass across the whole monitor space? What is the lighting like in the area? Where is the lighting in the area? What about natural light in the area? The only wait to know for certain is for you to try it, can you try it without removing the protective film?

@keven1508 - Film based one-way mirrors are a compromise. They’re marginal at best if you’re on a tight budget. The amount of light reflected just isn’t as good as a professionally built one-way glass. If you do insist on going with film, I would recommend taking the film and the glass to an automobile tint shop and asking if they’ll apply the film for you for a nominal fee. They have the experience and are probably the best people local to you to do it.