Finally, the card-holder! Probably made with a variation on saddle stitch where I sewed first one side, then the other. Sewn with cotton yarn, not very elegant haha. It can hold 4 cards comfortably on each side.
And this is how it compares to the notebook holder I've shown before
Yes, I finally posted it haha. Thank you!
I definitely need proper thread for my next project. I'm actually considering having fabric for the inside dividers/pockets, but we'll see. I might still have some thin and soft leather so that might work. We'll see :D