The $2,000 folding iPhone that goes on sale today starts getting a deeper crease down the middle of its screen within about a week of normal use. Apple planned for it. The top layer of that screen is built to be peeled off and replaced, and Apple will do it for $19. Tim Pan, a YouTuber, put an iPhone Duo on a folding machine and let it open and close 10,000 times at room temperature, then another 1,000 times inside a freezer at -4°F. The hinge still felt smooth at the end, which is honestly impressive. The screen is what you see in those photos, with a line running right down the middle. Before the machine even started, he folded a brand new one 500 times by hand, and the crease was already deeper. The industry has used 100 folds a day as its normal-use benchmark for years, so 500 folds is about five days with the phone. The full 10,000 works out to around three months, which is a lot less than the "years of use" people are reading into those photos. So why does a screen crease at all? Think about folding a receipt. You flatten it back out and the line stays. Apple's inner display is more than ten ultrathin layers stacked and glued together, and the plastics and adhesives in that stack act a lot like that receipt. Every time you close the phone, the inside of the fold gets squished and the outside gets stretched. Glass can't hold onto a bend like that. At room temperature it either springs back perfectly or it cracks. The plastics and glue slowly give in instead. Engineers call it creep, where the molecules relax a tiny bit into the bent shape every time and never fully go back. Any single fold leaves almost nothing behind, but after ten thousand of them you've got a shallow valley bouncing light right at your eyes. That's where Apple's matte finish comes in, the one it talked up at launch. It scatters light so the groove is hard to spot, which is why launch-day videos made it look like there was barely any crease at all. Fold it enough and the groove gets deep enough to show through anyway. So Apple treated the top layer like something that's going to wear out, because it is. Kate Bergeron, Apple's VP of hardware engineering, confirmed the cover layer can be removed and replaced. With AppleCare+ in the US, the swap costs $19. You'll pay more than that for a lot of regular screen protectors. A new layer won't erase the fold in the layers underneath. You're getting a fresh surface on top, the part your thumb touches and the light hits first, and that's meant to make the line a lot less obvious again. Carmakers landed on the same answer with brake pads a long time ago. Pads are going to wear down no matter what you do, so they're cheap and quick to replace. Apple couldn't beat the physics of folding a screen, so it turned the crease into a $19 part.