How to detect two way mirror and ordinary mirror?

Two way mirror is coated with a thin and almost-transparent layer of metal (usually aluminum). The result is a mirrored surface that reflects some light and is penetrated by the rest. It is used in special light condition, that one side bright, one side dark. People can see through the mirror from bright light side, but on dark side people can only see themselves. So it is also called privacy glass or half mirror. It is widely used in street observation room, shower room, bathroom, villa, police station, etc...

So how do you find the glass in front of you, is a two way mirror not a ordinary mirror? Finger test is a very popular way to determine whether a mirror is rear or not. However, it is flawed. 

Following is the method of finger test:

Place your finger on the mirror. if your reflection does no touch itself then there is a second layer of glass and you can be assured it is a real mirror. However, if your finger does touch the reflection directly there is a possibility that is a two-way mirror.

For more information of glass and mirrors for building and furniture decoration, please visit our website: www.sggglassmanufacturer.com

-----------------SUN GLOBAL GLASS from China