Updated 2026-11-01 · VEGO WINDOWFILM

This page collects the window tint terminology you run into on spec sheets, quotes and contracts, sorted into five groups: performance numbers, materials, installation, PPF and home glass. Within each group, entries run from A to Z. For a deeper look at how to compare the numbers, read our overview of window film specifications.

Here is where car owners usually trip up when reading a spec sheet: two abbreviations that look alike measure completely different things. One international brand's sheet lists the same film at IRR 90% ± 3 and IRER 66%, a 24-point gap caused only by a different measurement band and calculation method.

Our take, reasoned from the spec sheets we have read: nearly every number on a film spec sheet only means something if it answers three questions. Which wavelengths was it measured over, on what glass, and who measured it? Any term that can't answer those three is a sales pitch, not data.

Window tint terminology for performance numbers and testing

This is the group where you are easiest to steer, because the biggest number is not always the one that matters.

Term Meaning
6 mm test glass The clear glass used to calculate the numbers on many spec sheets. Tinted car glass gives different results.
ASTM E903, E308 Two standards often cited on spec sheets: E903 measures transmission and reflection, E308 calculates results for a standard light source.
g-value The European term, roughly equivalent to SHGC.
IRER The share of infrared energy blocked over 780 to 2,500 nm, calculated from SHGC.
IRR Infrared rejection over a band the manufacturer chooses, often very narrow. One brand lists 900 to 1,000 nm.
LSG VT divided by SHGC. A higher number means more light comes in relative to heat.
NFRC A US organization that rates the performance of windows and glazing. Certified films can be looked up in its directory.
SC Shading coefficient, an older metric. Rough conversion: SHGC ≈ SC × 0.87.
SHGC Solar heat gain coefficient, from 0 to 1. A lower number means less solar heat gets in.
SIRR One way of calculating infrared rejection: 100% minus what is transmitted over 780 to 2,500 nm. Energy the film absorbs and then radiates inward still counts as blocked.
Tolerance (±) The deviation the manufacturer accepts around the published figure. Example: IRR 90% ± 3.
TSER Total solar energy rejected, equal to (1 − SHGC) × 100%. Only comparable between two films with the same VLT.
U-factor Non-solar heat transfer, meaning heat moving through the glass because of a temperature difference. Lower insulates better.
UVR Ultraviolet rejection. UV is only about 3 to 5% of the sun's energy at ground level, so this number says nothing about heat.
VLR Visible light reflectance, with an exterior and an interior figure. Higher means the glass looks more like a mirror.
VLT Visible light transmission, the share of visible light (380 to 780 nm) that gets through. Higher means a lighter film.
VT The equivalent of VLT on window labels, weighted by the sensitivity of the eye.
WINDOW software A tool from the LBNL lab (US) used to calculate glazing system values to NFRC rules.

When choosing VLT for each car window, see the VLT article. The table above only explains terms; it does not recommend levels.

Film materials and construction

Material names on a quote are more marketing names than scientific ones, especially the word "ceramic". Asking exactly what layers a film has works better than trusting the name.

Term Meaning
Adhesive The layer that bonds the film to the glass. Adhesive quality affects clarity and long-term durability.
Carbon film Film using carbon particles, absorbing infrared more than reflecting it, with no metal.
Ceramic film Film with a ceramic layer, usually a nitride or oxide. The word is easily misused on cheap products.
Dyed film Film colored with dye, relying on absorption, low heat rejection, prone to turning purple unless it is a color-stable type.
Hard coat The hard layer on the film's face toward the room or cabin, which reduces scratches when cleaning.
Metalized film Film with a metal layer that reflects heat. The main risk is interference with device signals.
PET Polyester plastic, the base of most window films, including safety film.
Reflective film Film with a strongly reflective layer, so the outside looks like a mirror in daylight.
Release liner The protective sheet over the adhesive, peeled off during installation.
Sputtered film Film with an ultra-thin coating applied by vacuum sputtering. The coating can be metal or ceramic, so ask which.

These are general descriptions from industry material, mostly from manufacturers and tint shops. Individual products vary in quality.

Installation and aftercare

These terms rarely appear on spec sheets, but they come up a lot in arguments with the shop.

Term Meaning
Dot matrix (frit band) The band of printed dots around the edge of car glass. Film does not sit as flat here, so the edges can show a white haze.
Film removal Stripping old film and cleaning the adhesive off the glass. This labor cost is easy to forget when budgeting.
Hand cutting The installer cuts the film directly on the glass. The result depends on skill and how careful they are with the blade.
Heat shrinking Using a heat gun so the film takes the shape of curved glass before it goes on.
Plotter cutting Machine-cutting film from glass pattern data, keeping blades off the car's glass.
Slip solution Water mixed with a slip agent, which lets the installer adjust the film's position before squeegeeing.
Squeegee The tool that pushes water and air bubbles out from under the film.
Test patch A piece of film applied to one pane to check the color, reflection and real result before doing the whole house.
Water bubbles Small pockets of water left between film and glass, which usually disappear as the film dries. Different from bubbles caused by dust or failed adhesive.

PPF and paint protection film

PPF is a separate product family and does not block sunlight like window film. See real configurations on the paint protection film page.

Term Meaning
Aliphatic TPU, aromatic TPU Two branches based on the isocyanate used. Aromatic darkens more easily; aliphatic is used when color retention matters.
Ceramic coating A protective coating for paint, much thinner than PPF, and not a film. Don't confuse it with ceramic window film.
Edge wrapping Folding the film edge into the gap of a body panel to hide the cut line.
Mil A unit of film thickness, 1 mil = 25.4 µm.
PPF Paint protection film, a clear multi-layer film applied over the paint.
PVC A plastic stiffer than TPU. Manufacturer material says it yellows and cracks more easily.
Self-healing Light scratches in the top coat fade with heat. Deep cuts down to the TPU layer do not.
Top coat The uppermost layer of PPF, usually self-healing.
TPH A cheaper material than TPU. Sources disagree on whether it self-heals.
TPU Thermoplastic polyurethane, the main body of today's PPF, flexible and elastic.
Yellowing The film changing color over time. One well-understood material cause is that aromatic polyurethane darkens under light.
µm Micrometer, a thousandth of a millimeter. Many technical data sheets give the thickness of each layer in this unit.

The material comparisons in this table come from sales material, with no independent testing.

Home glass and architectural film

With home windows, the type of glass matters as much as the film. The reason is the risk of thermal cracking, covered in our article on window film for west-facing windows.

Term Meaning
Annealed glass Ordinary float glass, sensitive to thermal stress, which should be assessed before applying film.
Double glazing Two panes separated by a layer of air or inert gas, reducing heat transfer.
Double glazing edge seal The seal around the edge of a double glazed unit. Heat from the film can put stress on it.
Frame anchoring Fixing the edge of safety film to the frame so a broken pane stays in the frame.
Frosted film Film that makes glass translucent, blocking the view day and night, including your view out.
Heat-strengthened glass Heat-treated glass, stronger than annealed but weaker than tempered. Also called semi-tempered.
Laminated glass Two panes with a plastic interlayer, so the pieces stay attached when it breaks.
Low-E A low-emissivity coating on glass. Pilkington advises against applying film to this surface.
One-way film The everyday name for reflective film. The effect depends on which side is brighter, so it reverses at night.
Safety film Thick PET film that holds broken glass. Roughly 100 to over 525 µm thick, and it does not make glass unbreakable.
Static cling film Film that holds to glass by static, with no adhesive, easy to remove, but less durable in humid places.
Surface #4 Glass surface numbering: on a two-pane double glazed unit, this is the innermost surface, facing the room.
Tempered glass Toughened glass. According to EWFA, it withstands a temperature difference of about 250°C.
Thermal stress The tension created when a pane heats unevenly, the main cause of glass cracking after film is applied.
Window decals Cut or printed graphics and lettering applied for decoration and branding, not for blocking sunlight.

The most misleading term of all sits right in the product's name. In Vietnam, window film is commonly called by a name that literally means "heat insulation film". The Efficient Windows Collaborative page on window film states clearly that film blocks solar heat by reflection and absorption, but does not insulate meaningfully. "Heat insulation film" is just the familiar name. In technical documents, the more accurate term is solar control film. The word "dark" is misleading in a similar way. Pilkington's bulletin notes that more than half of solar energy lies outside the visible range, and a film that looks clear can still absorb a lot. Looking at a film's color won't tell you how much heat it blocks.

Next steps

If you find a line on a spec sheet this page doesn't explain, take a photo and send it to the VEGO team through the contact page. Include the film name and where you plan to install it so the answer fits your job.