How to read PPF specifications

First, check the unit

An 8 mil film is not 8 millimeters thick. One mil is one-thousandth of an inch, equal to 25.4 microns. A micron, written µm, is one-thousandth of a millimeter.

To convert mils to microns, multiply by 25.4. So 8 mil = 203.2 µm = 0.2032 mm. A product sheet may round that to about 200 µm. Keep the original number and any tolerance beside your conversion.

Next, ask what the thickness includes

The face film and adhesive stay on the car. The release liner is the backing removed during fitting. Some films also arrive with a removable protective cap sheet on top. Neither removable layer adds to the installed protection.

“Face film” can already include its topcoat. Check the manufacturer’s layer description before adding anything. The useful question is: does this number include the adhesive and exclude the liner and cap sheet?

A real example: 6.5 mil versus 7.8 mil

Avery’s North American Supreme Defense Gloss sheet lists a 6.5 mil face and 1.5 mil adhesive. Together that is 8.0 mil, excluding its separate liner. 3M’s Pro Series 200 Gloss sheet lists 7.8 mil for the film with adhesive, also excluding the liner and optional cap sheet.

So comparing 6.5 with 7.8 would miss Avery’s adhesive. On the matching basis, the listed totals are 8.0 and 7.8 mil: a difference of 0.2 mil, or 5.08 µm. That arithmetic does not tell you which film will stop more chips. Both sheets describe typical values, not a head-to-head protection test.

This example uses Avery revision 5, August 20, 2026, and 3M revision B, March 2024. It applies to those named films; a similar product name in another market may have a different sheet.

Choose the look, then read the material

Gloss gives a shiny, reflective look. Matte softens reflections; satin usually describes a softer sheen between a flat matte look and gloss. Those names are not a shared measurement scale. Compare physical samples on your paint rather than expecting every brand’s “satin” to look the same.

TPU means thermoplastic polyurethane, a type of flexible plastic used to make films, including PPF. BASF describes different TPU grades and film applications. The letters identify a material family; they do not reveal the whole film’s topcoat, adhesive, appearance or performance.

If a listing says “TPH,” ask the maker what the film is made from and request its technical sheet. We have not established one reliable definition that applies to every use of that label.

Self-healing and water beading answer different questions

Self-healing refers to recovery from certain light marks in the film’s surface. It does not mean a cut, deep scratch or damaged paint will repair itself. The conditions vary by product: 3M describes heat-assisted recovery for minor marks in Pro Series 200 Gloss. Follow your film’s care guidance rather than choosing your own heat treatment.

Hydrophobic describes water-repelling behavior, often seen as beading. Hydrophilic describes water-friendly behavior. XPEL’s reviewed STEALTH sheet actually calls its topcoat hydrophilic. Neither word, by itself, is a stone-chip protection score. Keep water behavior, cleaning claims and impact protection separate when comparing films.

A year count needs a label

Durability describes how long a manufacturer expects a product to perform under stated conditions. A limited warranty tells you which problems are covered, for whom, where and with what remedy. Even when the numbers match, they answer different questions.

For example, the reviewed 3M US/Canada card gives Pro Series 200 a ten-year term for named failures, subject to exclusions. It does not cover every impact or ordinary wear, and it applies to the original consumer purchaser. Ask for the warranty that applies where your car will be fitted.

Compare the test, not just the result

A number needs its method and conditions. ASTM’s gloss method includes measurements at 20°, 60° and 85°. A gloss value measured at one angle is not a ready-made comparison with a value measured at another.

For a scratch, stain or impact claim, look for the test method, sample, exposure, temperature, duration and way the result was judged. If the two products were tested differently, the figures do not settle which one is better. A “pass” without the supporting conditions is not enough to rank brands.

Use the film comparison to line up the published facts. If a box says a value is unverified, that means we could not confirm it from the reviewed source; it does not mean the film lacks the feature.