Another box in some kind of heavy/armored/industrial/SciFi design (similar to the vault crate), but this one has a clasp with a print-in-place screw on the front that locks the box shut, and no removable nut that can go missing. I'm a bit proud of that mechanism that I've not seen used elsewhere.
I've added a couple of different sizes. If you need a different size, leave a comment and I might add it; the "mini" is the smallest reasonable size, the “long” is long enough for most pens and can be used as pencil case. The numbers indicate inside dimensions. The boxes shown in the photos are the “2-decks-of-cards” and the “small” version.
Printing:
It's a print-in-place model, so no assembly required, also no support — just print and use.
However the hinges have medium-tight tolerances and require a well adjusted printer. Maybe try one of the smaller models first, and if the hinges won't move, try reducing the extrusion factor (filament settings) or maybe the XY size compensation (advanced print settings, set to a slightly negative value, e.g. -0.05mm).
0.4mm nozzle, 0.2mm layer height, standard settings.
The author marked this model as their own original creation.