The honest answer is: it depends which film you have. This is the single most important thing to understand about privacy film, because getting it wrong leads to disappointment after dark.
One-way mirror film: reverses at night
One-way mirror film relies on the outside being brighter than the inside. By day that gives you privacy and a mirror to the street. At night, with your lights on and it dark outside, the balance flips — so yes, people can see in. For rooms used after dark, pair mirror film with a blind or curtain.
Frosted film: private day and night
Frosted (and heavily patterned) film obscures the view by diffusing light, so it works the same whatever the light balance — full privacy day and night. That's why it's the go-to for bathrooms and any room where you need constant privacy.
How to get night privacy with a view by day
If you want your view out during the day but privacy at night, the usual answer is one-way mirror film plus a simple blind or curtain you close in the evening — the film does the daytime work, the blind handles the night.
The bottom line
Frosted film is private day and night; one-way mirror film is a daytime solution that reverses after dark. Tell us how you use the room and we'll recommend the right combination on a survey.
Thinking about window film? We offer a site survey anywhere in Scotland, with most quotes returned within 24 hours.