I needed an ID card holder for two cards at my work, and I didn't like any I found, so decided to design my own, as thin as I could. I've printed in PETG because sometimes I need to keep the cards in the car, so would handle better with the heat, but you can print it in PLA. Will even be easier to remove the supports. I find out the supports I've used worked well to remove. The fit is thigh, so will better if you calibrate you filament prior the printing.

Hope you enjoy it.