Apple continues testing ultra-thin glass in bid to hide foldable iPhone crease

Apple iPhone

Apple is still experimenting with advanced ultra-thin flexible glass as it works towards a book-style foldable iPhone, with a clear goal in mind: eliminating the visible display crease that continues to plague most foldable devices on the market today.

According to a report from a China-based industry source, Apple is testing a next-generation ultra-thin flexible glass solution that uses uneven thickness across the panel. The idea is to make the glass thinner specifically around the folding area to improve flexibility, while keeping other sections thicker to maintain rigidity, durability and overall structural strength.

This approach differs from the ultra-thin glass currently used in most foldable phones. Existing solutions tend to deform at the hinge over time, creating a visible crease where the display bends repeatedly. Apple’s proposed ultra-thin flexible glass is designed to distribute bending stress more evenly across the panel, rather than concentrating it along a single fold line. In theory, that could reduce the crease to a point where it becomes nearly invisible during normal use.

The testing phase is reportedly ongoing as Apple fine-tunes both the manufacturing process and long-term reliability targets. The foldable iPhone is still expected to debut in 2026, alongside the iPhone 18 Pro lineup, suggesting that this work is part of late-stage hardware validation rather than a fundamental shift in product timing.

While testing advanced display materials this late might appear risky, it does not necessarily point to a delay. Apple is likely moving from design validation into early production validation, a stage where the core hardware architecture is already locked in. At this point, high-risk components such as displays and hinges typically undergo extended stress testing and qualification to ensure they meet Apple’s durability standards.

In this context, Apple’s continued evaluation of ultra-thin flexible glass may be less about deciding whether to use the technology at all, and more about validating how it is applied. Apple is known to pursue aggressive engineering targets while maintaining fallback options, and more mature ultra-thin glass solutions could still be used if the newer approach fails to meet expectations at scale.

The report also suggests that multiple Chinese display manufacturers are now evaluating similar ultra-thin flexible glass technologies. That development indicates the material may be nearing commercial readiness, even if yields, costs and consistency still need refinement before mass production.

Beyond the display itself, Apple is expected to rely on liquid metal hinge components to further reduce visible creasing. The combination of a redesigned hinge mechanism and variable-thickness glass could allow Apple to deliver one of the cleanest foldable displays seen so far, at least visually.

The foldable iPhone is widely expected to adopt a book-style design, featuring an outer display measuring roughly 5.3 to 5.5 inches and an inner folding screen around 7.8 inches. Pricing is expected to be firmly in premium territory, with estimates ranging from $2,000 to $2,500, which would make it the most expensive iPhone Apple has ever produced.

If Apple succeeds in hiding the crease, it could significantly reshape perceptions of foldable phones, especially among users who have avoided the category due to visible wear and display distortion. For now, the continued testing suggests Apple is unwilling to compromise on one of the most noticeable weaknesses of foldable displays, even if it means pushing material science to its limits.