The iPhone Duo has one of the least visible creases on any foldable when it comes out of the box. A new lab test shows how quickly that changes with use.
HTX Studio scanned the crease on a new iPhone Duo in its iPhone Duo review, then folded the phone 3,000 times and scanned it again. The channel also put the inner screen through scratch and pressure tests and compared the results with other foldables.
The iPhone Duo Crease Grows From 48 to 167 Microns After 3,000 Folds
On a brand new iPhone Duo, the scan found a peak-to-valley height of 48 microns, about half the thickness of a sheet of paper. The slope across the center fold came in under 0.1 degrees.
HTX tested two other unidentified foldables, labeled Model A and Model B, along with a foldable from five years ago. Only the older phone showed a clear W-shaped crease, at 350 microns.
HTX then ran all three new phones through a folding machine for 3,000 folds and left them shut for a while before scanning again. Every crease got deeper, and the iPhone Duo measured 167 microns, about the same as Model A and worse than Model B.
The slope across the center rose to 1.24 degrees, worse than Model B and better than Model A. The HTX reviewer says the crease looked obvious on a demo unit after the launch event, which fits the way foldable creases deepen with use. The first reviews in our iPhone Duo review roundup mostly describe the crease as hard to spot when you look at the screen head-on.
The Nano-Texture Screen Resisted Pencil Scratches Better Than Another Foldable
Apple says the nano-texture finish reduces glare and minimizes crease visibility. HTX credits the same finish for a harder surface. Its rig pressed pencils from 6B to 8H against the inner screen with a constant 100 grams of force, roughly 1 newton.
- With a 6H pencil, the iPhone Duo picked up scratches that showed under bright light but were too light to feel.
- With an 8H pencil, the scratches were more obvious and could be felt by touch.
- Another foldable showed no scratches at 4H, but its scratches at 5H already looked worse than the iPhone Duo at 8H.
A separate pressure test used an Apple Pencil with increasing loads. At about 15 newtons, roughly 1.5 kilograms, the iPhone Duo left only a barely visible mark that was hard to feel, while another foldable left a permanent white mark at the same force. HTX points to the glass layers above and below the display panel, which it describes as ultra-thin glass.
The finish scatters light, which makes black areas look gray in bright ambient light instead of fully dark. HTX still says it hurts image quality far less than a typical paper-like screen protector and feels smoother. Apple says Apple Pencil support arrives later this year, and it is already working in iOS 27.2.
A Replaceable Cover Layer Costs $49, or $19 With AppleCare+
Apple lists the cover layer replacement at $49, or $19 with AppleCare+, in its published iPhone Duo repair fees. An inner display repair costs $999 without coverage.
HTX suggests leaving the iPhone Duo open while it charges. Foldables often ship unfolded because the materials inside the screen slowly deform under stress when folded, which deepens the crease until it settles.
In the same testing, the hinge held any angle from 15 to 165 degrees, about on par with Model A and better than Model B. HTX says it will buy an iPhone Duo after launch and fold it until it breaks.
