Samsung’s “Ultra Thin Glass” (UTG) display cover used in the new Galaxy Z Flip smartphone seems not to make the phone's screen more durable and rigid than the plastic displays.

A video on Youtube by Zack Nelson shows that the Z Flip’s display starts showing permanent marks and scratches far earlier than actual glass would. Part of the test is putting phones through a gauntlet of Mohs hardness picks to test when the display glass starts showing damage. According to Zack’s videos before, modern smartphones have “scratches starting at a level 6, with deeper grooves at a level 7.”

The Z Flip starts picking up damage at level 2 and more significantly at 3, which is on par with the plastic screens of the Galaxy Fold and more recent Motorola Razr.

Samsung said:

Galaxy Z Flip features an Infinity Flex Display with Samsung’s Ultra Thin Glass (UTG) to deliver a sleek, premium look and offer an immersive viewing experience,” a spokesperson said by email. “Samsung’s first-of-its-kind UTG technology is different from other Galaxy flagship devices. While the display does bend, it should be handled with care. Also, Galaxy Z Flip has a protective layer on top of the UTG similar to Galaxy Fold.

In any case, Z Flip buyers can get a one-time screen replacement for $119, Samsung says. In addition, you can also get a specialized screen protector designed for the Z Flip for free one time:

As part of Premier Service, we will offer a one-time free application of a screen protector for the Z Flip at select UBIF [U Break I Fix], Samsung branded locations or by sending it to Samsung Premier Service via mail,” the company added. “The screen protector will be applied by a specialist with the proper equipment to align and apply it. The program is rolling out soon.

Samsung (UTG) for the inner display is measuring in at only 3% the thickness of the glass conventionally used to protect smartphone displays. Even though it may be more aesthetically-pleasing, it’s even more fragile than transparent polyimide (plastic).