Industrial designers Gilli Kuchik and Ran Amitai designed Elastic Hinge, a metal-free alternative to eyeglass hinges. "Through the examination of various folding techniques from different fields," the duo writes, "we found ourselves inspired by the structure of tent rods and applied aspects of this technique to our glasses: an elastic cord is threaded in channels in the glasses frame and handles and allow for their folding, replacing the traditional hinge."

The design makes good use of (SLA) 3D printing. Voids left in the frames and stems serve as the channels to route the elastic cord. (Molding a similar arrangement would be possible, but it would also be expensive.) In one of the designs (blue and pink lenses, photo above), the elastic runs around each lens and back towards the stem on either side; in another design (blue-green lenses, photo above), the elastic spans from one side of the glasses to the other. Kuchik and Amitai purposely printed the glasses out of translucent material and used a brightly-colored cord, demystifying how the hinges work.

Here's what it looks like in action:

As certain materials become more expensive during supply chain woes, I'd like to see more experimental design projects like this, where designers take a commonplace object and ask: "What if we had to make these, but without material x?"