As Apple increasingly produces folding devices — from the rumored smart rings and a "folding iPhone" to the shipping MagSafe Duo Charger — it is researching how to make hinges stronger.

Apple continues to research hinge technology, planning slim but strong ones made out of composite materials for everything from a folding iPhone, to a MacBook Pro, and other wearables.

They never last forever without yellowing, but if you’re going to get a clear case, your best bet is Samsung’s first-party ...