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The Top Coating

What is Top Coat in PPF?

Hello everyone, hope you are all doing alright !

We have seen some product advertisements, articles online here and there, and a couple of times the information shared is not exactly passed on in its entirety integrity, inducing automotive professionals and final clients to have misconception about some products’ features.


A topic I saw recently was about PPF, what it is, what it is for, and the installation process. In this article, written on a famous sports magazine, it was advertised the PPF “Fast self-healing”, as being an advanced technology compared to the “conventional” PPF, and that struck me to the past, like 6 years ago when STEK brought to the market a PPF called “WS Shield“, on paper it would be a great product but we learned that its main feature was also one of its weaknesses: Fast Self Healing tends to be more prone to Contamination


To understand why, it is important to first understand what PPF construction is like. Simply put, a conventional transparent PPF is composed of 3 layers: Adhesive, TPU (Thermoplastic Polyurethane) and Top Coat.

TPU is the main material of this composition, it is the one that definitely protects the paint, but TPU despite being UV resistant, without a protection layer it would be exposed to adverse weather conditions. The most recent generations of PPF have their TPU protected by a coating layer that we simply call it “Top Coating“.

The Top Coating
It is a resin with anti-UV, hydrophobic and/or self-regenerating characteristics that is applied to the surface of the TPU film during the PPF production process. Its main function is to protect the TPU against the actions of time. The composition of Top Coating may vary depending on the PPF brand and also the product type.

Defense against Contamination

Top Coating is one of the frontline soldiers in the fight against contamination and scratches, consequently it is also a determinant of how the self healing function will play out in that film. Depending on the density of its molecules and the chemical composition of the top coating, the self healing function will act in different ways.


A top coating with high molecular density can be more flexible and has a self-healing effect that requires external assistance such as a heat gun. This type of coating, due to its characteristic of high molecular density, may turn it difficult or even preventing water and pollution residues from penetrating between the molecules and causing contamination. However, generally this film has little stretchability, hence a slightly more difficult to install.


A TPU with low molecular density top coating generally tends to be more flexible and has a good visible self-healing effect without the need for a heat gun, great to show how the technology works and great for marketing as the “SUPER AUTO CURING FILM”, but in reality, SUPER AUTO CURING films tend to suffer a lot from contamination over time. Fast/Super Self Healing films may look cool but will give you contamination and yellowing problem much often than high density coated films.


The best of all worlds would be the ideal density to provide the ideal self-healing effect without letting your guard down on contamination. STEK has developed a variety of coatings that have been used by many brands around the world. And with a special registered patent, the DYNOshield* line is contemplated with a special type of top coating that is used in a different way than the conventional ones. Instead of a layer applied over the TPU, STEK uses a technology that uses an infusion method within the structures of the TPU, this guarantees the DYNO line a clarity, brightness, flexibility and resistance to contamination unmatched compared to current products of the competition.

Discover the DYNO line by STEK and be part of the #STEKrevolution

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