About Visual Light Transmission or "VLT"

When reading through the descriptions and technical specifications of the Apex line of solar control,
automotive, and tinted security films you will often see a "VLT" rating for the window film.
VLT stands for "Visible Light Transmission" or sometimes referred to as visible light transmittance.

VLT is a window industry term that refers to the amount of visible light that passes through a
glazing system, (in this case window film) and is expressed as a percent. A lower VLT rating tends
to be better for glare control, while a higher rating is preferred for maintaining natural light.

VLT General Rule of Thumb: The lower the VLT number the darker the film!

VLT Spectrum Comparison Chart


The chart above will help you compare the amount of light that will be blocked by your solar, automotive
or tinted security films.

PLEASE NOTE: VLT only refers to visual light and does not effect Ultraviolet blocking qualities of window film.
In fact, even our highest VLT films still block more than 98% of UV rays. While there does tend to be a relationship
between visual light transmission and total solar energy rejection (TSER), Apex offers a variety of window films to
optimize light transmission and heat rejection.

To compare DIY solar control window film technical specifications, please click here.