How do 20% and 35% tint compare side by side?
35% roughly doubles the light of the 15 shades and gives up about 22 points of glare control; heat rejection changes by only 3 to 5 points within a film line. The numbers below are LLumar’s own (performance data sheet, LL0116NAEN, 03/26), measured to NFRC methods with each film applied to clear quarter-inch glass.
| 20% | 35% | |
|---|---|---|
| LLumar shades | IRX 15, ATC 15, or off-menu ATC 20 | ATC 35, IRX 35 |
| Measured VLT | 20% (IRX 15), 18% (ATC 15), 25% (ATC 20) | 38% (ATC 35), 39% (IRX 35) |
| Glare reduction | 78% (IRX 15), 79% (ATC 15), 72% (ATC 20) | 57% (ATC 35), 56% (IRX 35) |
| Total solar energy rejected (TSER) | 59% (IRX 15), 40% (ATC 15), 38% (ATC 20) | 54% (IRX 35), 35% (ATC 35) |
| Infrared energy rejected (IRER) | 61% (IRX), 22% (ATC) | 60% (IRX), 22% (ATC) |
| Visible reflection | 5–6% | 6% |
| Over privacy glass that passes 40% | About 7–10% | About 15–16% |
| Washington State, passenger cars | Under the 24% minimum | Over it on clear glass; depends on the car |
| Road-legal in BC | Behind the driver | Behind the driver |
Which LLumar shades become 20% and 35% at the shop?
35% is simple: ATC 35 or IRX 35, both on the menu. 20% isn’t on the menu, which jumps from 15 to 35, so it becomes IRX 15 (measured at 20%) or ATC 15 (18%). LLumar also makes an ATC 20, which measures 25%, but it isn’t on the shop’s menu.
The names and the measurements don’t line up exactly. A “35%” in either film lets through 38 or 39% on LLumar’s sheet, ATC 15 lets through 18% and ATC 20 lets through 25%. IRX 15 is the one shade here whose measurement lands on 20 exactly. The full set of options near 20%, IRX 25 included, is laid out on 5% vs 20% tint.
What changes on the road between 20% and 35%?
The car looks lighter, the cabin shows more, glare control drops by about a quarter, and you see more out of the side and back glass after dark. None of these changes is extreme; it’s a step, not a leap.
In daylight
A 20% film keeps the back seat in shadow from outside. At 35%, faces, child seats and shopping bags are easier to pick out, because the film passes twice as much light in both directions. From inside, 35% keeps the view over your shoulder closer to untinted glass.
After dark
At night you start with little light, so the ratio matters more than in daylight. IRX 35 passes 1.95 times the light of IRX 15; ATC 35 passes 2.1 times ATC 15 and 1.5 times ATC 20. On an unlit road, that’s light you’ll notice every time you check over your shoulder. The broader question is covered on is dark tint safe for night driving.
Glare
The 15 shades cut 78–79% of glare and the 35 shades 56–57%. If low sun through the rear side glass bothers your passengers, 20% handles it noticeably better.
Does 20% keep a car cooler than 35%?
Only slightly, and less than switching film. Within one line, 20% rejects 3 to 5 more points of total solar energy than 35%: IRX 15 59% against IRX 35 54%, ATC 15 40% and ATC 20 38% against ATC 35 35%. Infrared energy rejection is the same within each line (60–61% IRX, 22% ATC).
Across lines the picture flips. IRX 35 rejects 54% of total solar energy, 14 points more than ATC 15, while letting about twice as much light through. If the reason you’re thinking about 20% is a hot back seat, 35% in IRX deals with that and keeps the lighter look.
How do 20% and 35% look over factory privacy glass?
Both end up much darker than on clear glass, and 35% film over privacy glass usually finishes darker than 20% film over clear glass. Glassmaker AGC says the light transmission of its privacy glass is chosen by car line and application, “from 4.5% to 40% (ISO 9050), vs. higher than 70% for classical vision glass” (AGC privacy glass).
Multiply the two percentages for a rough result. Even at the light end of AGC’s range, glass passing 40%:
- A 35 shade (38–39%) leaves about 15–16% of the light.
- A 20% request (18–25%) leaves about 7–10%.
On darker privacy glass the results fall further still, so on that glass even a 35 makes a big change. Window tint vs factory privacy glass explains what the factory glass already does, and can you tint over factory tint covers the job itself.
Where are 20% and 35% legal, in BC and across the border?
In BC, either shade is legal anywhere behind the driver’s seat, rear window included when the car has two outside mirrors, since BC puts no darkness limit on that glass. In Washington State the 24% line falls between the two shades.
BC
Film is allowed in three places only by MVAR s. 7.05(8): side windows behind the driver’s seat, a rear window flanked by two outside mirrors, and a windshield strip reaching 75 mm down from its top edge. Neither 20% nor 35% is road-legal on the front doors, and the 2025 Vehicle Inspection Manual fails it there under item 13d. The shop fits front-door film when asked, and is clear first about the consequences. Mission RCMP gives $109 as the typical tint fine. Under a Notice & Order, the film comes off and the car has to clear an inspection at a designated facility, and leaving that for more than 30 days costs $598.
Washington State
RCW 46.37.430 requires “a light transmission of twenty-four percent or more” on every window except the windshield, counting factory tint and film together, and makes breaking it a traffic infraction for anyone driving on Washington’s public highways. Vehicles the manufacturer identifies as a truck, motor home or multipurpose passenger vehicle may go darker behind the driver. So on a passenger car, a 20% film is under Washington’s line before the glass is even counted; a 35 shade starts at 38–39% on clear glass, and whether the car stays above 24% depends on its own glass. If you cross at Aldergrove or Sumas in a sedan, that’s worth knowing; BC vs Washington tint laws compares the two in full.
20% or 35%: which should you choose?
Choose 20% if privacy and glare control come first. Choose 35% if you want a finished, tinted look with the easiest view out, or if the car already has privacy glass.
20% rather than 35% suits you if
- You want passengers, kids or cargo kept out of view.
- Low sun through the rear side glass is a regular complaint from the back seat.
- The car has clear rear glass and you want it to look close to factory privacy glass.
35% suits you if
- You want the car to look tinted, not blacked out.
- You drive unlit roads at night or reverse into tight spaces after dark.
- The rear glass is already factory privacy glass.
- You drive a passenger car into Washington State.
Where we stand
Decide by the glass you’re starting with. On clear rear glass, 35 gives a finished look and the easiest view out, and 15 is there if privacy matters more. On factory privacy glass, a 35 already lands darker than 20% on clear glass, so there’s little reason to go darker. Either way, if heat is part of the reason, ask for IRX. Full specs for both films are on LLumar IRX nano ceramic film, and every shade on the menu is compared on what tint percentage you should get.
What do 20% and 35% cost, and how long does the job take?
Both shades cost the same within a film. A sedan or pickup’s rear glass is listed from $240 in LLumar ATC, a sports coupe’s from $220 and a full-size SUV or wagon’s from $260; IRX is a per-package upgrade, as the tint price list explains.
Most cars are done in a day, and a complete SUV or sedan is typically a two-to-four-hour job, cut on the plotter to your exact model. Roll the tinted windows down only after three to five days of curing. Send the year, make, model and the shade you’re leaning towards through the window tint quote form.