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Old 10-25-2012, 04:48 PM   #662
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Originally Posted by johnebli View Post
Stock Ford glass is 70% so you have to take that into account when you tint.
Here is the formula:
glass% x film% / (glass% + film%) = real%
Example: Llumar CTX 30 is actually 31% so if you do the math...
31 x 70 / (31 + 70) = 21.5%

Just for a reference, Ford dark privacy glass that you find on the rear of vans and pickups is 17%-18% so you would need a film in the low 20's to make the front door glass match.
It doesn't appear to be 70% stock to me, more like 85-90% light transmission, its much much brighter than after the 30% film would be applied to the windows.
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