We fit screen protectors every single day at GenioTech, so we’ve had plenty of time to develop opinions on them. Customers ask us all the time whether they’re worth buying, and the honest answer is: it depends entirely on what you’re expecting them to do. Screen protectors are excellent at some things and genuinely useless at others, and the gap between a good one and a cheap one is significant.
Here’s everything we’ve learned from fitting hundreds of them.
What Screen Protectors Actually Protect Against
Let’s start with scratches, because this is where screen protectors earn their keep.
Phone screens are made from glass — typically a variant of aluminosilicate glass, such as Corning’s Gorilla Glass or Apple’s Ceramic Shield. Glass sits at around 5.5 to 6.5 on the Mohs hardness scale, which is a standard measure of how resistant a material is to being scratched by another material. Here’s the problem: keys, coins, and many other everyday items in your pocket or bag sit at a similar hardness level. Keys are typically around 5 to 6 on the Mohs scale. That means they absolutely can scratch phone glass — and do, every day.
Sand and grit are the real culprits most people overlook. Quartz particles, which are found in ordinary dust and sand, sit at a 7 on the Mohs scale — harder than most phone glass. If you set your phone face-down on a dusty surface, or if grit works its way into your pocket alongside your phone, those particles will score micro-scratches into the glass over time. You might not notice them individually, but under certain lighting conditions — particularly direct sunlight or a lamp at an angle — you’ll see a network of fine scratches building up across the display.
A good screen protector, sitting in front of the glass, takes all of those scratches instead. After a year with a screen protector, the protector itself looks battered. Your display underneath looks brand new.
What Screen Protectors Do Not Protect Against
This is where expectations need to be managed, particularly around drops.
A screen protector adds a very thin layer of material to the front of your phone. In a significant drop — say, face-down onto concrete from waist height — the physics don’t change meaningfully. The impact energy is still transmitted into the phone, and if it’s enough to crack the underlying display, a thin screen protector won’t stop that. We’ve seen cracked screens with entirely intact screen protectors sitting on top of them. The protector absorbed nothing.
Some premium tempered glass protectors are thick enough to absorb a modest amount of impact and may prevent cracking in lower-energy drops. But we wouldn’t want anyone walking around without a case thinking their screen protector has them covered. It doesn’t. Drop protection comes from a case, not a screen protector. The best outcome is to use both together — more on that below.
The Different Types — and Which Is Worth Your Money
Cheap Plastic Film
We’ll keep this brief: plastic film screen protectors are almost always a waste of money. They scratch easily — often almost immediately — and because they’re flexible, they distort the display slightly, reducing clarity and making touch input feel slightly off. They tend to peel at the edges after a few weeks. We don’t stock them, and we’d advise skipping them.
Tempered Glass
This is the one to buy. Tempered glass protectors are made from glass that’s been heat-treated to be harder and more shatter-resistant than standard glass. You’ll often see them marketed with a “9H hardness rating” — this refers to a pencil hardness test and means the glass resists scratching by a 9H hardness pencil, which is extremely hard. In practice, this translates to excellent scratch resistance for everyday use.
Tempered glass also feels exactly like the phone’s original glass under your finger, which plastic film never quite manages. Touch sensitivity is unaffected. The display looks exactly as it should. A good tempered glass protector, properly fitted, is almost invisible.
The quality varies significantly by brand and price point. Very cheap tempered glass protectors can be brittle or poorly cut for the specific phone model, leading to poor edge coverage or lifting at the corners. We source protectors that we know fit correctly and hold up over time.
Privacy Screen Protectors
These are tempered glass protectors with a micro-louver filter applied — the same technology used in privacy films for laptop screens. Looking at the phone straight-on, the display looks completely normal. From an angle — on a train, in a queue, in an open-plan office — the screen appears dark to anyone beside or behind you.
If you commute regularly, handle sensitive information on your phone, or simply don’t want strangers reading your messages over your shoulder, these are worth the small additional cost. The trade-off is that the display looks slightly darker and less vivid even when viewed straight on, and in very bright conditions you may find yourself needing to increase brightness slightly.
Anti-Glare Protectors
Anti-glare protectors have a matte coating that diffuses reflected light, making the screen easier to see in bright sunlight or under harsh artificial lighting. The trade-off is a slight reduction in display sharpness and vibrancy — the matte texture softens the image slightly. For people who spend a lot of time outdoors or work under bright strip lighting, the trade-off is worth it. For everyone else, a standard tempered glass protector is clearer.
Why Fitting Matters As Much As the Protector Itself
A good screen protector fitted badly is significantly worse than a good screen protector fitted well. The two main issues we see with self-fitted protectors are dust particles trapped underneath and air bubbles.
Even a tiny piece of dust caught between the protector and the screen creates a visible bubble. Once it’s there, there’s no fixing it without removing and replacing the protector — and if you’ve already peeled the adhesive layer, that’s often not possible without bubbling further. In a home environment, especially in a carpeted room, airborne dust is everywhere and settles on the screen in seconds.
Professional fitting in-store makes a significant difference. We have a controlled environment, proper alignment tools, and the technique to get a clean, bubble-free fit first time. It’s not magic — it’s just the right conditions and enough practice to know exactly what we’re doing.
The Case + Screen Protector Combination
We say this to every customer who comes in for a screen protector fitting: the two things together are dramatically more effective than either one alone.
A case protects the edges and back of the phone, and crucially, it raises the front of the phone slightly above the surface it’s resting on. This means that in a face-down drop, the phone hits the edge of the case first rather than the screen hitting the ground directly. That single factor prevents a huge proportion of screen breaks. Add a tempered glass protector on top, and you’ve got a setup that will see most phones through years of drops without a cracked display.
The screen protector handles scratches. The case handles drops. Together, they cover the two main ways phones get damaged.
Where We Come In
At GenioTech, we sell and fit screen protectors in-store from £5, for a wide range of iPhone and Android models. We’ll make sure it’s the right protector for your specific model, fitted correctly without bubbles or dust, in a couple of minutes.
To put the value in perspective: a screen protector from us costs £5 to £15 depending on the type. A screen replacement for a mid-range phone costs considerably more — and for flagship models, it can run to several times that. The maths are obvious.
If you’re picking up a phone after a screen repair, ask us about fitting a protector before you leave. It’s the single most cost-effective thing you can do to protect the repair you’ve just paid for. You can see our full range of services and accessories here, or just come in — we’re at 29 Hilltown, Dundee, Monday to Saturday, 9am to 5pm.
A £7 protector versus a £180 screen replacement. The choice makes itself.