A very simple divider for card boxes. Size matches Magic The Gathering cards in height and are slightly wider. Has a tab for stickers or other markers.
Added a version, which is smaller to fit into a deck box. The first version was a little to high.
Added versions with no tabs, only a simple plastic card.
I've printed it with 0.3mm layer, so it results in exact 2 layers, which are tough and flexible. Printed 30min for 2 dividers.