Paint protection film is a clear thermoplastic urethane layer, cut to the shape of your panels and applied over the paint. It sits between the finish and everything the road throws at it.
The material was originally developed to protect helicopter rotor blades from sand and debris erosion. That heritage tells you most of what you need to know about what it's good at: absorbing impact from small, fast-moving particles that would otherwise chip and abrade the surface underneath.
What it protects against
Stone chips. This is the main event. Motorway driving throws grit at your front end at speed, and every chip is a point where the paint is broken and corrosion can start. Film absorbs that impact.
Light scratches and swirls. Most modern films are self-healing — the top layer is designed so that minor scratches close up with heat, whether from sunlight or warm water. Deeper gouges won't heal, but the day-to-day accumulation of wash marks and brush scuffs largely will.
Chemical etching. Bird lime, tree sap and road salt are acidic enough to etch clearcoat if left. Film takes that damage instead of the paint.
UV fade. Quality films block UV, which matters most on reds and dark blues that fade fastest.
What it doesn't do
It won't stop a car park dent, and it won't survive a serious scrape any better than paint would. It isn't armour — it's a sacrificial layer that takes the small stuff so the expensive layer underneath doesn't.
A common misconception: PPF and ceramic coating aren't alternatives to each other. Film is physical protection against impact; coating is a chemical layer that makes the surface easier to clean and adds gloss. Plenty of people have both — coating applied over the top of film.
When it's worth the money
The honest answer is that it depends on three things: what the car cost, how you use it, and how long you'll keep it.
It usually makes sense on a car worth enough that a respray or panel refinish would be genuinely expensive, driven regularly on fast roads, and kept for several years. It also makes sense on anything you intend to sell on where paint condition affects value — which is most performance and premium cars.
It's harder to justify on a low-value car, a short lease where you hand it back regardless, or a vehicle that mostly sits in a garage and does short urban trips.
How long it lasts
Most quality films carry a manufacturer warranty of seven to ten years against yellowing, cracking and delamination. Real-world life depends heavily on how the car is stored and washed. Film that lives outside in strong sun ages faster than film on a garaged car.
It's worth being clear that a warranty covers the film failing, not the film wearing. A ten-year warranty doesn't mean it will look new for ten years.