How to protect the iPhone Duo's crease

Apple hasn't published any crease-care guidance for the iPhone Duo. The AP reported at launch that Apple hadn't posted any information on how to take care of the Duo, and as of Oct 25, Apple had not given official guidance on how to handle the phone, according to 9to5Mac.

So this guide keeps three things apart: what Apple's documents actually say (mostly troubleshooting steps, not care advice), what independent tests found, and general advice other foldable makers give for their own phones. The iPhone Duo crease explainer covers what the crease is and what counts as normal.

What Apple's documents say, doc by doc

Apple published a batch of iPhone Duo support documents on Oct 23, 9to5Mac reported, including troubleshooting guides for the hinge and for the displays. They're written for diagnosing problems, not for daily care.

Apple's display and Multi-Touch troubleshooting document is the source of the finger-pad and cleaning instructions, and it tells you to remove any case or screen protector before troubleshooting. Apple's Apple Pencil troubleshooting document likewise tells you to remove any third-party case, cover or screen protector when diagnosing problems.

Apple's hinge troubleshooting document covers a phone that won't open or close completely, unexpected noise, a loose, bent or broken hinge, and enclosure damage that affects the hinge, 9to5Mac reported. Its steps include checking the hinge for dust or particles, Macworld reports.

Apple's iPhone Duo Cover Layer document is a repair procedure that uses an inner display fixture and a roller, and it cautions against using hard or sharp tools to lift the layer. It doesn't address owner removal, but Apple's iPhone cleaning guide does: it calls the cover layer an integral part of the inner display and says, "Don't attempt to remove it."

What's missing is a folding guide. The Oct 25 9to5Mac report noted that some on social media say not to close the phone by pressing the center of the inner display, and said it is unclear whether that advice is relevant. Apple also hasn't shared hinge test results or a lifetime fold count, MacRumors notes.

As of Oct 31, 2026, Apple hasn't said anything specific about keeping keys, coins or cards out of the fold, or about cold weather. Samsung and Honor have given that advice for their own phones, per the AP, and the steps label it as theirs.

What the stress tests found

These are tests run by reviewers, YouTubers and repair specialists, some on custom fold machines. They show how the hardware behaved under repetition or abuse, not how long any one iPhone Duo will last, and the testers didn't publish care advice from them.

Joanna Stern folded her review unit more than 32,000 times over four nights with a custom machine, MacRumors reported. A push-pull gauge showed the hinge was stiffer afterward, though Stern said it felt "pretty much the same as day one." The machine opened the phone flat but didn't fully close it each time, and the phone had a case on.

HTX Studio scanned the crease before and after 3,000 folds, iThinkDifferent reported. Crease height rose from 48 microns to 167 microns, and the slope across the fold went from under 0.1 degrees to 1.24 degrees.

In JerryRigEverything's test, dust got into the hinge through several entry points despite the IP68 rating and overwhelmed the magnets that hold the phone closed, per MacRumors. A separate bend test left a permanent green line across the inner display before the screen became unresponsive. In the same video's scratch test, the outer screen marked at level 7 on the Mohs scale and the inner screen at level 2, MacRumors reported.

iFixit's teardown found that dust made the hinge crunch, though it collected less than the Galaxy Z Fold8 or Pixel 11 Pro Fold, MacRumors reported. iFixit also traced the reported cracks to an area near where the gap for the crossing flex cable meets the central hinge support, without reaching a firm cause.

Cases and screen protectors

As of Oct 31, 2026, Apple hasn't said that a case protects the crease or the inner display. The best iPhone Duo cases guide shows which designs wrap the hinge.

If your case overlaps the left edge of the outer display, Apple's case document points to a Shift Left Edge setting in Settings > Display & Brightness, 9to5Mac reported.

Inner screen protectors are a separate debate, covered in should you put a protector on the inner screen. As of Oct 31, 2026, Apple hasn't said whether third-party inner protectors are safe.

If you see a line or crack

Apple acknowledged the inner-display problem on Oct 26. In a statement shared by Bloomberg's Mark Gurman, Apple said the issue affects "a small number of iPhone Duo units" and told owners with display problems to contact AppleCare for a replacement, iClarified reported.

Owners have described cracks down the center line of the hinge, followed by a horizontal block of pixels stuck glowing white, according to 9to5Mac. As of Oct 31, 2026, Apple hasn't said how many units are affected and hasn't released a failure rate.

Apple's statement, as reported by iClarified, doesn't say whether replacements are free. iClarified, citing Bloomberg, described mixed store experiences: one owner at Apple's Fifth Avenue store received a replacement after staff collected details for an early field failure analysis, while another was left waiting because his store had no replacement device.

For damage Apple treats as accidental, the fees climb quickly without coverage. As of Oct 31, 2026, MacRumors lists US fees of $999 for inner display damage without AppleCare+ and $99 with it, and $49 or $19 for cover layer damage. AppleCare+ for iPhone Duo costs $399 upfront, $199.99 a year or $19.99 a month in the US, and whether AppleCare+ is worth it runs the numbers.

Bottom line

Apple hasn't told owners how to protect the crease. What exists is a set of troubleshooting steps (finger pads, Apple's cleaning method, checking the hinge for dust), Apple's instruction not to remove the cover layer, other makers' advice for their own foldables, and Apple's instruction to contact AppleCare if the inner display fails. That's thin, and we'll update this guide when Apple publishes more.

Have you changed how you carry or fold your iPhone Duo since launch?