Deck box for Magic The Gathering cards (sleeved). The two halves slide in each other to create the box. One half is used as library, the other as graveyard.
Images shown are for version 1. (*)
1.2 improved the sides on the library half.
1.3 further improvements based on comments by drcameron: made the library sides a bit thicker and higher; added 2 windows (idea from remix by ambrosiol) and added candles (just for fun).
Feel free to remix, see link on Tinkercad
(*) I was not yet able to print 1.3 because of trouble with my Zortrax.