I needed a card holder for work that could carry five or more cards.
It works nice and I use mine every day. I made mine in PLA and it is sturdy.
Do not fill it to the top with cards, It works best with 6 cards but it can hold 7 without problem. It takes 9 cards but it gets tight. You may damage the top card if you have to remove it often. As I wrote, 6 cards is ideal.