A side-by-side comparison of every screen protector material on the UK market — and which is actually right for your phone, tablet, watch, or laptop.
The short answer: tempered glass for ~90% of phones and flat-screen tablets. Flexible film (TPU or hydrogel) for foldables, smartwatches, curved-edge displays, and small-screen devices where impact protection matters less than scratch resistance and conformity.
That covers most readers. If you want the full picture — including which film type, why glass thickness matters, and where the marketing claims break down — read on.
| Material | Hardness | Impact | Best For |
|---|---|---|---|
| Tempered Glass (9H) | ★★★★★ | ★★★★ | Flat phone & tablet displays |
| PET Film | ★★ | ★ | Budget, scratch-only protection |
| TPU Film | ★★★ | ★★ | Curved screens, foldables, watches |
| Hydrogel | ★★★ | ★★★ | Foldables, self-healing scratches |
Tempered glass screen protectors are made from soda-lime or aluminosilicate glass that's been chemically strengthened (usually via a potassium-ion exchange). The glass is then coated with an oleophobic anti-fingerprint layer on top and a silicone adhesive layer underneath. Quality protectors are 0.25–0.33mm thick. Cheap ones are 0.4mm+ — which is where you start losing in-display fingerprint compatibility.
Every tempered glass on Amazon is "9H" hardness. This is a pencil-hardness scale where 9H is the hardest pencil you can buy. It means a 9H pencil dragged across the glass under standard pressure won't scratch it. It does not mean the glass is harder than diamond, harder than your screen, or unbreakable. Modern phone screens (Ceramic Shield, Gorilla Glass Victus) are also rated 9H. Don't pay extra for "10H" or "12H" claims — those numbers don't exist on the standard pencil hardness scale and are pure marketing.
PET (polyethylene terephthalate) is the original screen protector material. It's the thin, glossy plastic film that came included with phones in the early 2010s. It's still widely sold today as the cheapest option — typically £2–£5 for a 5-pack.
PET film offers minimal protection. It scratches easily, doesn't absorb impact, and the adhesive picks up dust during installation. For a tablet that lives in a case all day, it might be enough. For a phone that goes in pockets with keys, it isn't.
When PET makes sense: ultra-cheap protection on devices you don't care about, kids' tablets, or as a temporary stopgap until proper glass arrives. PET protectors on Amazon UK →
TPU (thermoplastic polyurethane) is the rubbery flexible film used on curved screens and foldables. It's significantly tougher than PET — properly self-healing in the case of minor abrasions. The flagship TPU brand for phones is Spigen NeoFlex; for foldables, it's the standard inner-display option.
TPU film protectors on Amazon UK →
Hydrogel is a recent variant of TPU/silicone-based film with enhanced self-healing properties. Marketed heavily on Amazon UK in 2024–2025, hydrogel sits between TPU and glass on most metrics — better self-healing than TPU, better conformity to curves, but still not as drop-protective as glass.
The marketing around hydrogel is heavy. The reality: it's a perfectly good option for foldables and curved screens, slightly better than basic TPU. For flat phone screens, you'd still take glass over hydrogel. Hydrogel protectors on Amazon UK →
A textured coating that diffuses reflected light. Excellent for outdoor use, kills the mirror effect of standard glass under sunlight. Trade-off: reduces sharpness slightly. The most popular variant is the Paperlike (which is also engineered for Apple Pencil friction). Paperlike on iPad is the standout use case.
Tempered glass with a louvre filter laminated inside that restricts the viewing angle to ~28°. Side viewers see black. Trade-off: 20–30% brightness reduction. Read our full privacy screen guide.
Whitestone Dome's specialty — UV-cured liquid adhesive flows under tempered glass to bond perfectly with curved displays. The only solution that gets a true edge-to-edge fit on curved Samsung phones. Fiddly to install, premium pricing. Whitestone on Amazon UK →
→ Tempered glass, 9H, alignment-frame brand. Spigen EZ Fit.
→ UV liquid glass (Whitestone Dome) or TPU film.
→ Glass on outer cover, TPU/hydrogel on inner display only. Never glass on inner.
→ Tempered glass for clarity. Spigen / Supershieldz.
→ Matte film. Paperlike.
→ TPU film + bumper case combo.
→ Tempered glass + bumper case combo.
→ Tempered glass, multi-pack, replacements ready. Supershieldz / amFilm.
No it isn't. The 9H rating is a pencil-hardness scale. Diamond's hardness is around 10 on the Mohs scale (a different scale entirely). No commercially available phone screen protector approaches diamond hardness — and you don't need it to.
Liquid "screen protectors" (typically nano-silicate sprays) deposit a microscopic layer of silicate on the screen. They add no measurable impact protection and only marginal scratch resistance. Some include accidental damage insurance — which is the actual product they're selling. Stick to physical glass or film.
Real sapphire would cost 50–100× more than tempered glass and be too hard to laser-cut economically. The "sapphire" protectors on Amazon UK are marketing-branded tempered glass. Don't pay a premium.
For most readers landing on this page: buy tempered glass. Pick a brand with an alignment frame (Spigen Glas.tR EZ Fit) and you've solved 95% of the protector problem. Reach for film only if you have a curved or foldable screen, a smartwatch, or you're protecting a device that doesn't see drops (kids' tablet inside a chunky bumper case).
Now go fit it properly — read our step-by-step install guide for a bubble-free finish.