The two-way mirror that will be used in this project has an important property. When one side of the mirror is exposed to a brighter ambient light than the other, this light is reflected in the mirror surface and is allowed to pass through to the other (darker) side of the mirror.

Typically, this property is used to control how the mirror is used in security applications, for example, a shop may fit such a mirror between an office and the shop floor so that those in the office can still see what is happening on the shop floor. For this to happen, the office must have very minimal lighting to ensure that the bright light from the already well-lit shop floor passes through to the office and that no light from the office leaks through the mirror, exposing it to the shop floor.

In our project, we will use this property to create a display that shows white text and graphics on a mirrored background by placing a section of the mirror in front of an LCD monitor.

This is possible if you keep the display dark in the areas where the mirror surface should be preserved and use bright white text and graphics where they should be shown instead of the mirror surface. By doing this, you can allow them to pass through the mirror surface provided that the brightness of the display is greater than that of the ambient light in the room the project is in.

For this reason, it is worth noting that this project will not work if the mirror surface is subject to bright sources of light, so it is best to keep the mirror pointed away from large windows or lights.

While searching for a suitable monitor, it is also better to get the highest combination of brightness and contrast ratio possible, as this will allow you to get brighter text and graphics from the display. This in turn will improve the quality of the image on the mirror surface while maintaining a dark background so as not to cause any light leakage where the display should remain a mirror.