DIY Window Film: When It's OK and When to Hire a Pro
https://magic-wiki.win/index.php/How_Window_Film_Improves_Energy_Star_Rated_Homes
Glass is a patient material. It holds heat, refracts light, and carries the fingerprints of daily life. Window film is a simple, sometimes transformative way to tune how a window behaves without replacing glass or altering the structure of a room