I really wanted a business card case that would also give me somewhere to put business cards that I receive from others as well. This design is loosely inspired by the Business Card Case from ekaggrat, but ultimately I ended up designing this from scratch.

This is designed to be assembled without additional hardware. The retention protrusions (in the sides of the base) are dual sided to allow the holder to allow either top piece to go on either end, though they will only fit properly on one side. The retention protrusions are oversized to allow for them to be trimmed to obtain the desired amount of force to open and close.

I obtained the best results by rotating the individual components to be vertically oriented and then using a raft to prevent lift.