Why the preview uses measured numbers, not shade names
The number in a film's name is a product code, not a measurement. LLumar's spec sheet measures ATC 50 at 60% visible light and IRX 05 at 6%, so a preview built from the names would be wrong at both ends. This one uses the measured figure for each shade, taken on clear 6 mm glass.
Looking out versus looking in
From the driver's seat you're looking at bright daylight through the film once, so a 35% shade lets through about a third of the light, and your eyes adjust. From outside, daylight has to pass through the film to light the cabin and then back out through it to reach someone's eye. That's roughly the square of the number, which is why a car with 35% tint looks much darker from the sidewalk than it feels inside. It's also why moderate shades give real daytime privacy.
Shades that suit the Fraser Valley
The dark months are long here. Environment Canada's normals for Abbotsford show 241 mm of rain in November against 43 mm in July, so a shade that feels right on a July afternoon can feel dim on a November evening. Behind the driver, 15% to 35% is the usual middle ground between privacy and seeing out at night, and 5% is the darkest the shop installs. The tint percentage answer goes through each choice, and the 20% versus 35% comparison covers the most common decision.
What the preview can't show
It can't show heat. A clear AIR film can reject more of the sun's infrared than a dark dyed one, so darkness is the wrong way to choose for comfort; the heat rejection comparison has those numbers. It also can't show factory privacy glass, which most SUVs and vans already have on the rear windows. Film over that glass stacks, and the stacking calculator estimates the result.
Seeing it on your own glass
Any of these shades is legal behind the driver in BC on a vehicle with two side mirrors; none is legal on the front doors under MVAR s. 7.05(8). Ask the shop on the Langley Bypass which shade suits your car and your driving before you book. Rear-glass tint starts at $240 on a sedan in LLumar ATC.