Had a loose pile of box knife blades in my toolbox. Looked here and didn't find anything to help, so designed something.
Designed in both FreeCAD and OpenSCAD. The OpenSCAD version is configurable by how many blades it will hold. The design will slightly modify if you have 50 or less blades and again for only 5 or less.
Slot at the bottom of any with more than 5 blades so they can be pushed out the front, from the back. 5 or less blades, just use the hole at the bottom to pop them up and pick one.
Files included are for 100 and 50 blades for the OpenSCAD version and
100 blades for the FreeCAD version.
As always, all source files included so you can modify as much as you want.
Printed the FreeCAD version in ABS and it fits well.
Printed the OpenSCAD version in PLA and its a little loose. Attribute that to ABS shrinking, so suggest ABS. It's also supposed to be stronger.