Two Way Mirror – How it works, where to buy & more info


What is a Two Way Mirror?

A two way mirror (also sometimes called a one way mirror – makes more sense if you think about it), is a mirror that reflects light but is also semi-transparent. So you get a mirror image on one side, but on the other side you can see through the mirror quite easily.

A glass two way mirror is 70% reflective and 11% transparent.

How do two way mirrors work?

The two way mirror works best if one side (the reflective side) is well lit, and the other side dark. This makes two way mirrors perfect to make smart mirrors. Since the brightness from the monitor can shine through, so it looks like the text “floats” on the mirror surface.

For the best effect, the light on the front and back of the mirror have to have the correct ratio. The optimal ratio needs to be at least 1:2. That means the light in front of the mirror needs to be two times stronger than the light coming from the other side. For best results, the ratio should be 1:6.

The two way mirror is created by putting a thin layer of aluminum on glass that has a gray tint. The aluminum is attached to the glass using heat, so it’s more resistant to scratches or rips than the mirror film.

Comparison of Two-Way Mirror glass (left) vs. VanityVision Smart Mirror Glass (middle) vs. Acrylic two way mirror (right)

We recommend using glass two way mirrors for making a smart mirror. Find out which glass is best for your smart mirror

What is a Two Way Mirror Film?

Two way mirror film is an adhesive film that you apply to a clear glass or plastic surface, to create a two way mirror effect. This is a cheaper solution than a glass mirror, but you lose optical quality and sharpness in turn. However, the film often blocks a bit too much light, so not enough light passes through to the other side, making text on smart mirrors appear dim or hard to read. Like noted before, smart mirror glass lets 11% light through, while film only lets 5% light through. You can use mirror film to make a smart mirror

Making a Smart Mirror With a Two Way Mirror

To make your magic mirror/smart mirror, you need a two way mirror. The most popular option is getting a plastic mirror, most often made from plexiglass. It’s a cheap option that’s easy to find online and local stores. Another option is getting a real glass mirror. This is a little bit more expensive, but if you can afford it, it looks much better than the plastic ones. The guys at are professionals and offer incredibly high quality glass that is suitable for magic mirror making. I recommend their VanityVision or SmartMirror glass.

The third option is using a mirror film on normal glass. Many people have been buying this type of film, with good results. But I recommend using it on glass instead of plastic, since the plastic tends to warp, creating a “fun-house” kind of effect on the mirror.