My teacher was actually talking about this today and he said its like a film. So I assume its kind of like window tint. He said is was fun slashing a piece of glass with that on it with a sledgehammer and seeing it not break
to install that film correctly you'll need to remove each pane so that the applied film will be "in the frame" when done. Just putting it on will only leave you with alot less of a mess to clean up. The galss will break right at the frame line and practically roll right up & out of the way.
I dont see why you dont just cover the windows with some cloth that can be easily moved aside to let light in. Nobody is going to break in if they can't see what they are gonna get. And if they know what is in there, they are gonna get in there no matter what