VLT (Visible Light Transmittance)
VLT (Visible Light Transmittance). VLT (Visible Light Transmittance) measures the percentage of visible light that passes through a window film. A 35% VLT film lets 35% of visible light through; a 5% VLT film lets 5% through (much darker).
Definition
Visible Light Transmittance is the single most-discussed spec when a customer is choosing a window film. It is expressed as a percentage and is independent of UV rejection, infrared rejection, and solar heat gain — those are separate ratings on the film manufacturer's spec sheet. A window's effective VLT also depends on the glass it is bonded to; a film sold as 20% VLT will measure lower on tinted factory glass.
Common VLT ranges by use case
Front windshields: typically 70%+ VLT to remain legal in most U.S. states. Front side windows: 35–50% VLT in many states, but state limits vary widely. Rear side and rear windows: down to 5% VLT (commonly called "limo tint") where legal for the back row of a vehicle.
State legal limits
Every U.S. state sets its own VLT limit per window position, and many measure it on the combined glass + film, not the film alone. Some states (e.g., California) cap front-side at 70%; others (e.g., Florida) allow lower numbers. A reputable tint shop confirms the customer's state limits before quoting.
Why VLT matters in shop software
Tint shop software that knows VLT is a first-class field on every line item can: filter the customer-facing catalog by what is legal in the customer's state, automatically include VLT in the warranty certificate, and prevent quoting a film that would be illegal on the customer's vehicle.
See also
- Ceramic window tint — Ceramic window tint
- Window tint shop software — Window tint shop software
- Automatic warranty certificate — Auto warranty cert
Roffik's take
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