I found a living-hinge box at the thrift store, and brought it home to study it. I decided to try my hand at making such a box. After a few prototypes with non-PG ply, I decided to eat up some cheap material instead. My choice was to use a cardboard box I got from the grocery store (a box of canned veggies).
The design works perfectly with my cardboard (0.125"), cuts in about 5 minutes, and I hot-glue in a minute. My final outer dimensions = 5-1/2" tall x 4" wide x 7/8" thick.
box, small, living hinge A".pdf (421.7 KB)
Please note that the top and bottom panels have design lines in them that should be set to Ignore. There are two ‘closing tabs’–chose the one you want to use, you don’t need both. (Photos show difference.)
Originally I designed the hinge for wood that was having trouble bending. It might be too much of a good thing for cardboard. It’s very compliant, so gentle handling is best. You see in the last photo I have the elastic cord taped in–at this point I was not sure how long I wanted the loop to be.
The two holes in the closing tabs and the top of the box are for alignment and strength if you feel you need it. Round wooden toothpicks, 0.08" diameter, will fit; trim to fit or use as design elements.