Living Hinge HPDA

This is a simple living hinge to help keep a stack of index cards used as a HPDA (if you haven't come across that term its Hipster Parietal Disgorgement Aid) and you can read about the history on wikipedia

https://en.wikipedia.org/wiki/Hipster_PDA

! The original HPDA, a binder clip and index cards is still a classic but after a week or so my cards always used to get scruffy/dog eared.