Ceramic vs carbon vs dyed tint: what you are actually paying for.
A 20% dyed film, a 20% carbon film and a 20% ceramic film look the same from the sidewalk. Inside the car they are three different products. Dyed film absorbs a little heat and fades. Carbon film holds its color for life and stops about half the infrared. Ceramic film rejects most of the infrared at any shade, which is why it is the only film worth putting on California-legal front windows.
Shade and heat are two different things
The number on a film, 5, 20, 35, 70, is visible light transmission. It tells you how dark the window looks. It says nothing about heat. Heat comes mostly from infrared energy, which you cannot see, and how much of it a film stops depends on what the film is made of, not how dark it is. That is the whole reason ceramic film exists: you can have a 70% film that looks almost clear and still stops more infrared than a dark dyed film.
The four film types, side by side
| Film | How it works | Heat rejection | Lifespan | Sides + rear |
|---|---|---|---|---|
| Dyed | Dye in the adhesive layer | Low. Absorbs some heat, re-radiates it into the cabin | Fades and turns purple in 2 to 5 years | Cheapest. Not something we install |
| Carbon (STEK ACTION+) | Nano-carbon particles | TSER up to 55%, IRER 36 to 49% | Will not fade or purple; limited lifetime warranty | Sedan $540, SUV $670 |
| Ceramic (STEK SMART+) | Tungsten-infused nano-ceramic | TSER up to 60%, IRER 55 to 63% | Limited lifetime warranty; in stock | Sedan $680, SUV $840 |
| Graphene ceramic (STEK NEX+) | Graphene-infused ceramic | TSER up to 64%, IRER 62 to 66% | Limited lifetime warranty | Sedan $940, SUV $1,200 |
TSER and IRER figures from STEK USA published specifications; ranges span the shades in each line. Prices are our Oakland shop prices for sides and rear.
Dyed film: the one we do not install
Dyed film is what a $99 special usually is. A dye layer in the adhesive darkens the glass and absorbs a little heat, then re-radiates it into the cabin. UV breaks the dye down over two to five years; the film goes purple, the adhesive bubbles, and the removal costs more than the install did. It is fine for a car you are selling next year. We do not carry it.
Carbon film: stable color, moderate heat
Carbon film replaces dye with nano-carbon particles. The color is permanent, the film carries a lifetime warranty against fading, and there is no metal to interfere with signals. Heat rejection is real but modest: STEK ACTION+ stops up to 55% of total solar energy and 36 to 49% of infrared depending on shade. If the car sleeps in a garage and you want the look and the UV block for the least money, this is the honest answer.
Ceramic film: heat rejection at any shade
Ceramic film uses ceramic nanoparticles, in STEK SMART+ tungsten-infused, that reflect and scatter infrared energy rather than soaking it up. Two things follow. The glass stays cooler to the touch, and the heat rejection holds even on light shades. SMART+ 70, the film we put on legal front windows, rejects 63% of infrared while passing 69% of visible light. That combination is impossible with dyed or carbon film. SMART+ is the line we keep on the shelf, in 70, 20 and 05.
Graphene ceramic: the top of the range
STEK NEX+ adds graphene to the ceramic layer. Graphene conducts heat sideways across the film instead of letting it concentrate at the glass, so the film runs cooler and rejects a little more: up to 64% total solar and up to 66% infrared. On a black car with a glass roof parked outside in Walnut Creek in August, the difference over SMART+ is noticeable. On a silver sedan in a Berkeley garage, it is not. That is the honest way to decide whether the extra $260 on a sedan is worth it.
How to choose
- Parked outside, afternoon commute, EV or crossover with a big glass area: ceramic (SMART+) at minimum. Consider NEX+ if the car is dark and the roof is glass.
- Garaged, mostly want the look and UV protection: carbon (ACTION+).
- Front windows in California: ceramic only. A 70% carbon film is legal but barely does anything for heat; a 70% ceramic does most of what a dark film would.
- Selling the car within a year: skip tint, or accept that a cheap dyed job is a cosmetic choice with a short life.
Bottom line
Pick the shade for the look. Pick the film for the heat. If heat is why you are tinting, ceramic is worth it, and it is the only film that lets you keep the front windows legal and still feel the difference. Shades, spec tables for every film and prices are on the window tint page, and the legal limits are in our California tint law guide.
FAQ
Is ceramic tint worth it?
If you park outside, commute in afternoon sun, or drive a car with a lot of glass (any Tesla, most crossovers), yes. Ceramic film rejects roughly 55 to 66% of infrared energy compared with about half that for carbon and very little for dyed film, and it does it at any shade, including the near-clear 70% film that California allows on the front windows. If the car lives in a garage and you mostly want the look, carbon film gives you the same shade for less.
Does ceramic tint look different from regular tint?
No. Shade is set by the visible light transmission number, and a 20% ceramic and a 20% carbon look the same from outside. The difference is what happens to the infrared energy you cannot see. That is also why ceramic is the only film that makes sense on legal front windows: a 70% ceramic looks nearly clear and still cuts the heat.
What is the difference between ceramic and carbon tint?
Carbon film uses carbon particles to absorb heat and block UV; it is stable and will not fade, but its infrared rejection tops out around 50%. Ceramic film uses ceramic (in STEK's case, tungsten-infused) nanoparticles that reject infrared instead of just absorbing it, so the glass itself stays cooler. Graphene ceramic goes a step further by spreading the absorbed heat across the film rather than holding it at the glass.
Why does dyed tint turn purple?
The dye breaks down under UV. As the blue and green components of the dye fail first, the remaining red shifts the film purple, and the adhesive often bubbles at the same time. None of the three films we install is dyed, and all three carry a lifetime warranty against fading and bubbling.
Will ceramic tint block my phone or FasTrak?
No. Older metallized films caused signal problems because they contained a metal layer. Ceramic, carbon and graphene films have no metal, so cellular, GPS, satellite radio and toll tags work normally.
What do TSER and IRER mean?
TSER is total solar energy rejection, the percentage of all incoming solar energy (visible, infrared and UV) the film stops. It is the honest heat number. IRER is infrared energy rejection measured across 780 to 2,500 nanometers, the industry-standard infrared band. Some brands quote a single-wavelength infrared number, which looks higher; STEK publishes both, and we quote the full-band figure.