Can you tint glass to be completely non seethrough?

Method 1: If 1 or 2% VLT isn’t dark enough for you, for example on a garage with valuable things inside, there isn’t really any tint film that is completely impervious to some sort of light. Even on the darkest, most reflective tint, it’s still possible to look through the glass if someone really wants to. At night when it’s dark outside but well lit inside, you’ll be able to see inside no matter what. You can make it so it’s completely impossible to see inside, but you won’t be able to outside at the same time. If it’s important for you that no one ever sees through those windows under any circumstance, then the only real fail-proof thing you can do is paint the window with Krylon. This is paint though, not tint, meaning it will no longer function as a window. No one will be able to see through it from either side no matter what.