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PMD Index™ Methodology

How we score a film, one document at a time

Every brand claims their film blocks heat, resists yellowing, and lasts for years. PMD Index checks which of those claims the brand can actually prove— and flags the ones it can't. It is our own independent read, calculated from the brand's own published data. No brand pays to be rated, and none can pay to score better.

Published data only

Scored from technical data sheets, catalogs and warranty documents — never marketing copy. Every source is linked on the product page.

One rubric for everyone

The same yardstick applies to a global brand and a local importer. There is no paid placement.

Silence is not neutral

An undisclosed critical spec counts against the score — a brand can't improve its rating by staying quiet.

Step one: how much is the evidence worth?

Before anything is scored, every captured value is graded on how well the brand backed it up. This is the part most product comparisons skip entirely — they treat a lab-certified number and a brochure claim as if they were the same thing. They are not, and PMD Index does not.

Verified

The brand states the number and cites a named test standard alongside it — ASTM, SAE, QUV, ANSI/NFRC. This is the only tier that counts as proof.

Brand-stated

A real number, published by the brand, with no test standard behind it. We show the figure — but it counts for less than a verified one, and we say so on the product page.

Not disclosed

We could not find this spec in any catalog, technical data sheet, or warranty document the brand has published. It counts against the score.

Why we don't just skip undisclosed specs. If a missing spec were simply excluded from the calculation, a brand hiding a weak result would score higher than one publishing an honest one. So for the specs that matter most, an undisclosed value is scored the same as a disclosed-bad value. Silence is never rewarded.

What we measure — Paint Protection Film

PPF sits on the outside of your car and has to survive years of sun, stone chips and chemicals — so the rubric is weighted toward the things that cause real failures, not the things that look good in a brochure.

Mechanical Performance

Tensile strength, elongation at break, gloss

Whether the film resists stone chips, wraps curves without tearing, and looks the way it should.

Heaviest

Chemistry & UV Weathering

Aliphatic vs aromatic chemistry, cited accelerated-weathering results

The single biggest predictor of whether a film yellows in Indian sun. Also the spec brands are quietest about.

Heaviest

Adhesive & Removal Safety

Peel/adhesion strength, whether a named adhesive supplier is disclosed

The biggest real-world failure risk: an unproven adhesive can pull your paint off when the film is removed years later.

Major

Functional Durability

Self-healing type, cited stone-chip testing, hydrophobic behaviour

The day-to-day behaviour you actually notice — swirl marks fading, water beading, easier washing.

Supporting

Thickness Fit-to-Optimum

Total film thickness against the industry-consensus optimum

Thicker is not automatically better — too thick becomes difficult to install cleanly on curves.

Supporting

Warranty Transparency

Stated coverage length

A brand's own confidence signal — but it's a promise, not a lab result, so it carries the least weight.

Minor

What we measure — Sun Films

Sun film is a different product with different failure modes, so it gets its own rubric rather than a reused one. There is no exterior weathering risk, and construction type drives almost everything — so it carries the most weight here.

Heat and glare are scored within a darkness tier. A darker film always blocks more heat than a lighter one, whatever it's made of. Ranking a 20% VLT privacy film against a 70% VLT windshield film on raw TSER would just be measuring darkness, not quality. So films are grouped into light, mid and dark tiers first, and heat and glare are only ever compared inside the same tier. VLT itself is never scored — a dark film isn't worse than a light one, it's for a different job.

Film Technology

Dyed, metallic, carbon, hybrid ceramic, nano-ceramic, or multi-layer optical

What the film is physically built from determines almost everything else about how it performs and how long it lasts.

Heaviest

Total Solar Energy Rejected (TSER)

Share of total solar energy blocked, scored within the film's VLT tier

The honest heat-rejection number — unlike IRR, it accounts for the full solar spectrum, not just infrared.

Major

Glare Reduction

Glare cut, scored within the film's VLT tier

Driving into low sun or oncoming headlights at night.

Supporting

Infrared Rejection (IRR)

Share of infrared blocked

The heat you physically feel on your skin through the glass.

Supporting

Interior Reflection

Visible light reflectance

High reflectance means dashboard glare and a mirror-like effect on your own windows after dark.

Minor

Signal Safety

Whether the film interferes with GPS, FASTag or mobile signal

Metallic films can degrade signal. A pass/fail fact, not a lab measurement.

Minor

UV Rejection

Share of ultraviolet blocked

Protects skin and interior from sun damage. Weighted lightest because almost every real film now clears 99%.

Minor

What we publish, and what we don't

We think you deserve to know exactly what goes into a score and to check every source yourself. We also won't hand brands a blueprint for gaming it.

Always published

  • Every spec we measure, and why it matters to you
  • How much each one matters, in plain words
  • The credibility grade behind every single number
  • That undisclosed specs count against the score
  • Every source document, openable and checkable

Kept proprietary

  • The exact weighting formula
  • The thresholds that turn one score into another
  • How much a bare claim is discounted versus a verified one

If a brand knew the precise cut-offs, it could disclose the bare minimum needed to clear them and stay quiet on everything else. Keeping the formula closed is what keeps the score honest.

What PMD Index is not

It is not our own laboratory testing.

We do not run independent lab tests. We read what brands publish, grade how well they backed it up, and score it consistently. Where a brand cites a real test standard, that is the brand's test — we tell you so and link the document.

A low score is not always a bad product.

It can equally mean a brand publishes very little. That's still useful to know before you spend money — but it's a disclosure signal as much as a quality one, and we show both numbers so you can tell them apart.

It does not rate the installer.

Even an excellent film fails if it is badly fitted. PMD Index rates the material only.

It is not final.

Scores change when a brand publishes new data or we obtain a document we didn't have. If you think we've missed something, tell us and we'll re-check it.

See it on a real product

Every scored product shows its full breakdown, the credibility grade on each spec, and links to the brand documents behind them.

Live today for PPF and Sun Films. Coatings, DIY and Interior PPF are next.