I made this case for my multisportcard and i did it in colours of my favourite gym and its logo but here is uploaded clean model.

On the back is hole for easy barcode reading so you dont have to take it out.

You can see that its not perfect and it has some artefacts, but it works just fine.

Printed on Prusa MK3s+ and nozzle 0.4mm

Printing:

1. Print basic plate which works like bridge for printing top layers.
2. Slice 2nd object (case itself) and set changing filament when the spot for 1st object is printed.
3. Make sure 1st object in straight a put it on 2nd object. (i recommend to use some glue or hair spray so it sticks better)
4. Put the 1st object on the top of the 2nd object and continue printing.