Privacy film can create a one-way mirror, depending on light conditions. Mirrored glass, if correctly applied, can create a mirrored effect on one side of the glass permanently, regardless of light levels on either side. Safety film (Also called Security film"), is designed to prevent the glass shattering under impact stresses, and to safely contain the glass if shattering does occur. This is sometimes used on glass that has already shattered, to provide some integrity while replacement glass is sought.