Samsung started to adopt ultra-thin glass covers for its foldable AMOLEDs, instead of polyimide, as it says UTG offers higher durability. In the Galaxy Z Flip, Samsung used a UTG cover produced by Korea-based Dowoo Insys, who processes Schott's ultra thin glass for Samsung Display.
In April 2020 it was reported that Samsung Electronics wants to develop its own UTG cover technology, as as it feels that Samsung Display's UTG is still not robust enough and the company also wants to increase production yields and reduce costs. Now there are new reports from Korea that say that Samsung Electronics is collaborating with Corning in this new UTG project.
It is interesting to see how Samsung Electronics and Corning compete with Samsung Display and Schott on this technology.