My wife and I really like the mod style cases that Mattel created in 2010 for games like uno, apples to apples, skip bo and other games.  I created some 3d printable card cases inspired by that design.  Now for the back to school contest, Ive decided to turn it into a pencil case that should be sturdy and simple enough to print

outside slip cover prints with no supports when placed on its end.  Insert also prints best standing on its end as I have done in the project file.  To print this you will need a prusa mk3 or mk4.  Theoretically you could cut these parts in half for a mini but you will lose strength that way.

It might be fun to personalize the slip case using prusaslicer.

The original case had a slip cover made in two halves with the front being clear and colored to match the back.  This was too hard for me to duplicate in a way that I felt would be stroing enough, but of course you are welcome to try.  

Otherwise, I recommend printing the inside in white and the outside in a clear filament of whatever color you prefer, but of course, I look forward to seeing what the community has to come up with.

Mod away!