The real thing everyone should vouch for, is glass. We take it for granted until we manage to shatter it by a careless drop. Glass is easy to see through, hard to scratch, durable and strong. It is also extremely foldable, probably more than we would like to think. But when it comes to flexing for smartphones that open up like books, it isn’t there yet. The head of glass giant Corning’s Gorilla Glass business, John Bayne, said, “Glass today, the current choices out there, they’re not optimal for folding smartphones. In a glass solution, you’re really challenging the laws of physics, in that to get a very tight bend radius you want to go thinner and thinner, but you also have to be able to survive a drop event and resist damage.” Currently, folding phone manufacturers are dependent on plastic polymers. This helps the materials to not only bend as far as you need them to, but you could also do it repeatedly.