How Does Window Film Work?
Tint is created when tinting film is bonded onto a piece of window glass. Tinting film is
usually made out of clear polyester film with a very thin and even layer of tinting
agents such as dyes and/or metals deposited onto the film.
A common misconception is that window tint is dark, and night-time driving is
impossible when a car is tinted. The truth is that there are films of ANY darkness that
suits your preferences. Also, unlike sunglasses that do impair your ability to drive at
night, tinting film is designed to reduce glare and not impede night-time driving. State
window tint laws also protect consumers against illegal tint that may put them in
harm’s way during night-time driving.
Another misconception is that window tint is bonded onto the outer surface of auto
glass. Window tint is applied on the inner surface which also protects the film itself
from flying debris outside the car.
Once tinting film is applied to a window, the characteristics of how visible light comes
into the car changes. Normal auto glass without tint reflects around 5% of visible light
(known as VLR%), absorbs another 5% (known as VLA%), and transmits 90% of
visible light (known as VLT%) into the car.
Depending on the type and quality of tinting film applied to a window, these
percentages change dramatically. Some tint are more reflective, and others absorb
more light. The number you will most commonly see is the VLT% (Visible Light
Transmittance). Almost all the official names of films include the VLT% within it like
Johnson Executive PBC30 or Madico Charcool CH-55. VLT% tells you how much
visible light is allowed to shine into the car, and also indirectly how dark the tint looks.
Tinting film doesn’t just block visible light. It also blocks harmful cancer-causing
ultra-violet (UV-A and UV-B) rays as well as infra-red (IR) rays that cause heat to
build up in your car; however, how effective a film is in blocking these rays depends
on the type of film, the manufacturer, and the quality of installation.