One of the FAQs on the iPhone Duo product page is about the crease, and Apple's answer describes the display rather than answering the question. The inner screen is flat and smooth, it says, with a nano-texture finish and optically clear adhesives that let the layers glide as it folds. The press release goes a step further and says the finish minimizes crease visibility, which is a statement about how much you see rather than about whether it is there. MacRumors reported that neither the FAQ nor the press release carries a fold cycle count.
Samsung does publish that number. The Galaxy Z Fold 8, which is roughly the same shape, is rated for 500,000 folds. What Apple offers instead is a hinge with more than 100 components and support ribs and a titanium panel under the display. On size, the Duo lands two records at once. It is Apple's thinnest iPhone at 5.2mm unfolded, 0.4mm under the iPhone Air, and its heaviest ever at 254 grams. Folded, it is 11.3mm. Pre-orders start October 16 and it ships October 23.