This box is part of a set that I’ve designed to give as gifts, the full list is at the bottom. The external dimensions are 155x22x22 and the internal 151x18x18 making it big enough for most modern oversized fountain pens.
There are two versions of the box, one with rounded edges, one without.
The standard clearance (SC) lid is a light friction fit for me but I’ve also included a slightly higher clearance (HC) version in case anyone has problems. The toggle is not generally required to hold the case shut but it is a nice cosmetic flourish, can be used to attach accessories and adds some security.
The pen is not my design and all credit for that goes to dinissantiago04
I recommend printing at 0.2mm layer height and 100% concentric infill
3D Printed fountain pen: https://www.thingiverse.com/thing:5353026
Four Hole Toggle: https://www.printables.com/model/226877-four-hole-toggle
Ruler: https://www.printables.com/model/227402-simple-ruler-and-compass
Stencil: https://www.printables.com/model/227408-simple-stencil
Portable Pen Rest: https://www.printables.com/model/226879-portable-pen-rest
The author hasn't provided the model origin yet.