Does Factory Tint Count in Washington?
Yes - the law counts your factory glass and your film together. That surprises almost everybody.
The short answer
Yes. Washington measures your factory glass and your added film together. The statute calls this "net film screening", and it is why a 35% film on already-tinted rear glass can land well under the limit.
The definition that decides it
Subsection (2)(b) of RCW 46.37.430 defines net film screening as "the total sunscreening or coloring material applied to the window that includes both the material applied by the manufacturer during the safety glazing and any film sunscreening or coloring material applied after the vehicle is manufactured."
That single sentence is the whole answer. The legal limit applies to the combined result, not to the film you bought.
Why this catches people
Film is sold by its own VLT. A film labelled 35% blocks 65% of the light reaching it. But if the glass underneath is already at 75% VLT, the combination is not 35% — it is roughly 26%. Put that same film on rear glass that came from the factory at 20%, and the result is far below any legal limit for a front window.
The multiplication is approximate, but the direction is not: the result is always darker than the film's own number. Anyone quoting you a film percentage as though it were your finished VLT is either guessing or does not know the rule.
Factory privacy glass is not film
The dark glass in the back of most SUVs and minivans is not tint applied to the surface — it is glass that was dyed during manufacture. Subsection (6)(a) makes clear that shaded or heat-absorbing safety glazing applied at the time of manufacture is not prohibited by the film rules. It is legal exactly as it sits.
But it still counts toward net film screening the moment you add film on top of it. The glass is legal on its own; the combination is what gets measured.
What this means in practice
It means the only honest way to quote a front-window job is to meter the glass first. We carry a meter and use it before recommending a film, because the same product produces a different legal result on two different cars. A shop that quotes you a percentage over the phone without knowing your vehicle is quoting the film, not your car.
Front glass is usually near-clear from the factory
On most vehicles the front side windows are close to clear, often somewhere in the seventies for VLT, because the federal safety glazing standard is stricter there. That is why front windows have the least room to work with and why they are where the legal problems happen.
Questions we get
Does factory privacy glass count toward the limit?
On its own it is legal under subsection (6)(a). But once you add film over it, the law measures the combined result as net film screening.
So a 35% film does not give me 35% VLT?
Correct. The finished number is always lower than the film's rating because the glass underneath blocks light too.
Can you measure my glass before quoting?
Yes, and we would rather do that than guess. The same film gives different results on different vehicles.
Do I need to remove factory tint?
No. Factory-dyed glass is part of the glass. It cannot be removed, and it does not need to be.