I made this custom case for my 3D printed spectacles:
It holds the glasses by the edge of the frames, so the lenses are suspended above the bottom of the case without touching anything and no padding material is necessary to prevent scratching.
And being specially sized for those glasses, the case is no larger than it needs to be.
Did I mention that I love 3D printing? 🙂
It has a long piece of 1mm piano wire running through that acts as a spindle. It’s a standard hinge design called a continuous hinge. I suppose I could have 3D-printed the spindle but it would have made the hinge huge and not very nice-looking.