Is the One Way Mirror Privacy film effective at night time?

The reflective/mirror quality of the films will offer varying levels of privacy, depending on exposure to sunlight and will only work during daytime/daylight hours. The films effectiveness depends on a greater light intensity on the exterior side of the window. When it's dark outside and lights are on inside, the effect reverses, making the interior visible to the outside. At night you would need blinds or curtains or similar to compensate. Therefore, this film might not be suitable as a privacy film for North facing or shaded windows that don’t receive much sunlight, nor if you are after Nighttime privacy in addition to daytime. In any of these instances, Frosted Window film would be better suited.