If you've shopped for window tint in San Antonio, you've heard the percentages: 5%, 20%, 35%, 70%. Usually without much help understanding what they actually mean for your car. Worse, you've probably been told "ceramic tint" and quoted a price that didn't make any of it feel clearer. Let's fix that.

What VLT actually means

VLT stands for Visible Light Transmission. It's the percentage of visible light that passes through the film and glass combined. Lower number, darker tint.

  • 70% VLT: nearly clear. Common for windshields. Blocks IR heat and UV without changing the look.
  • 50% VLT: light shade. Noticeable from outside, still very easy to see out of at night.
  • 35% VLT: moderate. The legal sweet spot for Texas front side windows (which must stay at or above 25%).
  • 20% VLT: dark. Common rear-window shade. Good privacy.
  • 5% VLT: "limo tint." Privacy only. Hard to see out of at night.

Texas tint law, the practical version

What Texas actually says:

  • Front side windows: 25% VLT minimum (so 25%, 35%, 50%, 70% are legal; 20% and darker are not)
  • Windshield: Top 5 inches may have a sun strip (any darkness)
  • Rear side and back windows on multi-purpose vehicles (SUVs, vans, trucks): any darkness allowed
  • Rear side and back windows on passenger cars: any darkness allowed
  • Reflectivity: must stay under 25%

Translation: on a sedan, you can legally do 35% on all sides + windshield strip. On an SUV, you can do 35% on the front and as dark as 5% on the rear if you want privacy. Reputable installers won't go below 25% on front side windows, and ShineLab won't either unless we get the legal exemption in writing first.

The much bigger variable: IR rejection

Here's what most tint shops won't lead with: VLT is not the same as heat rejection. A dark dyed tint at 5% VLT can block less heat than a clear ceramic tint at 70% VLT. The film's heat performance comes from IR rejection, how much infrared energy it blocks, and that's a function of the film's technology, not its darkness.

Three film categories you'll see in San Antonio:

1. Dyed film

Cheap, no real IR rejection, fades to purple within a few summers. Avoid for daily drivers in Texas.

2. Carbon film

Middle tier. Better than dyed, doesn't fade, blocks some IR. Acceptable for budget jobs but not a meaningful heat solution.

3. Ceramic / nanoceramic film

What ShineLab installs. Non-conductive ceramic nanoparticles that block 60–70% of IR heat and 99% of UV. No interference with cell signal, GPS, key fobs, or radio. Doesn't fade. The only film worth installing on a car you plan to keep in Texas.

If your only consideration is darkness, dyed tint will do it cheaply. If your consideration is keeping the cabin cool and the interior from cooking, ceramic is the only category that delivers, and the difference is measurable on a hot day with a thermometer.

What we recommend for San Antonio drivers

If you want the cleanest look

Match all-around: 35% ceramic on every window. Legal on the fronts, dark enough on the rears to look intentional, dramatic heat reduction across the board.

If you want maximum privacy on an SUV

35% ceramic on the front sides, 15% or 20% ceramic on the rears (factory tinted glass often reads ~20–25% from the factory, so a 20% film stacks darker). Add a 70% ceramic to the windshield for heat block without changing the look.

If you have leather and a south-facing parking situation

Don't skip the windshield. UV through the windshield does more to age leather than any other source. Add a 70% ceramic windshield film and you'll cut interior surface temperatures by 15–25°F on a hot day.

If you have a Tesla 3 or Y

The glass roof is the single biggest heat liability. A ceramic film on the roof glass is the highest-ROI tint you can buy on a Tesla. We tint hundreds of square inches of glass for less than the cost of one A/C compressor replacement.

What about kids, skin, and the actual reason most people tint

UV exposure through car windows is real. Side glass on most cars is not UV-rated like a windshield — drivers in Texas pick up measurable UV damage on the left side of their face and arm over years of driving. Ceramic tint blocks 99% of UVA and UVB, full stop. If you've got kids in the back, leather you want to keep, or skin you want to protect, ceramic tint isn't a cosmetic upgrade. It's basic protective gear for living in this climate.

What it costs to do it right

Real ceramic tint for a sedan starts at $399 at ShineLab. SUVs from $549. Trucks and Teslas from $599. Includes a lifetime film warranty against fading, bubbling, peeling, and delamination. We install legal-compliant VLT by default and we install mobile or at your home.

If you've been quoted "ceramic" for $250 in San Antonio, ask which brand and what the IR rejection rating is. Real ceramic film costs the installer more than that in materials alone. There's nothing wrong with budget tint as a price decision. Just go in knowing what you're buying.