Riddles in the Dark (The Hobbit) in puzzle box form!
post-processing and demo

Don't forget to set Z-Seam Alignment to Random. Artifacts will reveal the solution as it is printed in the solved position.

I would love to see some more riddles which could be put in this format. These boxes could make a nesting set...

It cannot be seen, cannot be felt,
Cannot be heard, cannot be smelt.
It lies behind stars and under hills,
And empty holes it fills.
It comes out first and follows after,
Ends life, kills laughter.

This thing all things devours;
Birds, beasts, trees, flowers;
Gnaws iron, bites steel;
Grinds hard stones to meal;
Slays king, ruins town,
And beats mountain down.

Another one from getriddles.com

Each day many people from all over the world come and visit me, however they usually only stay for a few minutes. I am considered by many to be very dirty yet few people would want to live without me. And, whenever people come see me, they reveal to me a part of themselves that they rarely show to others.

Here's a nice one from Riddles From A Recluse by Wallace Pustinjak

Unlike other rulers I am strengthened by neglect.
Over my jurisdiction, great taxes I elect.
When routine dues are paid, I am weakened severely.
Yet if too long delayed, it may cost you quite dearly.
My vault is of the flesh, my tellers silver and bone.
The upkeep of the kingdom is financed with a loan.

Post-Printing

Run a sharp edge around the rings to free them up (see video). Magnets (3mm x 6mm OD) may be optionally added, paired with nuts/washers to require the box open with a sudden stop.