Hey,

I hope you like this print flat box, from what I know it is an original idea but I haven't looked too hard. all the same, it should work great for holding small parts or pet 3d printed rock (coming soon)

https://www.thingiverse.com/thing:2832416

TO MAKE: Print. then heat the joints by dripping hot water on them. then fold gently and hold firm. (fold all of the tabs first) once you have all of the folds, you can glue to tabs for extra strength or just remove them.

as always if you have any questions feel free to ask and ill get back to you shortly. :)