Yes. We recommend a dark and/or reflective film. To achieve the desired effect, one should have brighter lighting outside of the space you are trying to have privacy in. During daytime the dominant source of light is outside, so you should have good privacy. At nighttime, if there are bright lights on inside, and it is really dark outside, people will be able to see in. If there are blinds in the space, closing them at night will eliminate the chance of someone seeing in.