When Samsung launched its original foldable smartphone, it used a polyimide-based cover, and the screen was fragile and not very durable. Later in 2020 Samsung Display launched its ultra-thin-glass (UTG) cover (produced by Schott and processed by Dowoo Insys) which the company said is more durable the the Polyimide.

Samsung Electronics continued to adopt the new foldable UTG cover and used it in its Samsung's Galaxy Z Fold2 5G (7.6" 1768x2208 HDR10+ 120Hz Dynamic AMOLED) smartphone. But the question remains - just how more durable is the UTG-protected OLED?

Zack Nelson from JerryRigEverything reviewed the Galaxy Z Fold 2, and you can see the review above. It turns out that the foldable display achieves the same Mohs scale of hardness score - 2. Which means that you can create permanent manage with a strong fingernail scratch (not something that you normally do, though).

The screen is of course protected when not in use. Zack also tested how it behaves when contacted by dust and rubble - and it seems that Samsung improved the hinges and design which means that small debris no longer enters into the inside of the phone like in the original Galaxy Fold.

All in all it seems as the durability of the phone is quite better than the previous model, which is good news. We also know that Samsung Electronics wants to develop its own UTG cover technology, as as it feels that Samsung Display's UTG is still not robust enough. According to reports SE is collaborating with Corning.

Just to compare, Zack also tested the the outer display - which is a 'regular' AMOLED covered with glass which achieves a 6 on the Mohs scale of hardness.

Samsung Galaxy Z Fold 2 photo

Kyulux - Hyperfluoresence OLED emittersKyulux - Hyperfluoresence OLED emitters