You know the police station interview rooms in movies? The suspect sits in a room with good lighting and a mirror on the wall. The police are in a dark room with no lighting, watching through the mirror. The ‘mirror’ is a double layer film. The highly reflective film faces one way, and is laminated to a low reflection film facing the opposite direction. The film is installed on the police side of the glass, with the more reflective side facing the suspect.
With higher lighting in the interview room, the suspect sees a mirror of themselves, and the low light level on the police side is washed out. The police can see through the glass clearly, as their side is low reflection and there is plenty of light from the brighter side transmitting through the film to them.
When it comes to one-way mirror films, there are many film types to choose from. What matters are your preferences regarding how reflective and how dark the film is.
For something as vital as an interview room, a very high reflection and dark film works best.
For something not so vital, where just a degree of privacy is required, a lower reflection and lighter film fits better. This will allow more light into the room and not darken it as much.
Selecting the right film is always subjective. The client’s idea of a dark or light room may vary from your own. That’s why its so important to talk to us about your expectations for the best balance.
The film will only work when it’s brighter outside than inside, i.e. daytime. At night when the light balance swaps, the neighbours will be able to see in.In the case of a bedroom, the low reflective side would be facing into the room. At night, the end user would not see a mirror on the glass, but the neighbours can see in. It would therefore be necessary to close blinds or curtains at night for privacy. There is no film that can provide night time privacy other than a frosted film.