Double layers of 20% vs Single 5% layer ; Which is Darker?

[WatchingYou]

Practically, Is a double layer of 20% tint darker than a single layer of 5%?

 

Theoretically, 20% * 20% = 4% which is a lower VLT than a single 5%, but I read some posts about how this formula doesn't really apply to real life and etc...

[drtint]

How do you get 4%? I get 10% minus VLT for the glass.

Please post findings. Have a great day

[florida tinter]

black vinyl is darker

 

[jh812]

According to the meter the double 20 is darker. Visually imo though the 5 looks darker. Keep in mind you always have to worry about warranty issues when doing two layers.

[WatchingYou]

31 minutes ago, jh812 said:

According to the meter the double 20 is darker. Visually imo though the 5 looks darker. Keep in mind you always have to worry about warranty issues when doing two layers.

 

Thanks for the help! So if the meter says double 20s is darker, then I think it practically is darker. It may look lighter to the eye when you hold the 2 pieces together because they're not 100% flush until you actually install them, I think. 

[jh812]

Yeah I don't know, naked eye I think you could tint two windows side by side and know the difference with it. 

[Tintmaster08]

It’s the same basically, 5% is two layers of 20 put together during the manufacturing process, so doubling up 20 is basically doing the same. You’ll have a +/- 2 either way of variance between the two which is considered normal because of the process of you putting two layers together vs the manufacturer is slightly different

[DynamicATL]

As said above, results will be close, but I would say 5% will be a touch darker.  It depends on the film too...Llumar ATC 20 is typically around 19 on the glass while 3M Crystalline 20 is typically around 13.  Plus why tint a vehicle twice for virtually the same result of a 5%.  

[Tintmaster08]

As said above, results will be close, but I would say 5% will be a touch darker.  It depends on the film too...Llumar ATC 20 is typically around 19 on the glass while 3M Crystalline 20 is typically around 13.  Plus why tint a vehicle twice for virtually the same result of a 5%.  

Right, the main reason I see double layer tinting is when The customer already has 20% and they say it’s not dark enough but do not want to pay for the removal so they just want you to tent over it.

[Apex Tint]

I agreed to double layer because the customer didn’t want to pay for removal on the back glass. Lasted about two years before it started peeling up. Probably won’t ever do that again.