I wanted a better way for my wife to be able to store her Magic: The Gathering cards then some cardboard boxes in a rack, so I bought some IKEA Alex drawers and made a card catalog that fits each drawer nicely, with an emphasis on the trays being accessible and removable without being too heavy. Originally these were a Gridfinity design, but I found after some iteration that this worked better for my use case. I have the Gridfinity version on my profile still but this is the one I use and printed. Elements of this design are still using references to the Gridfinity system but the actual grid is gone.

These are specifically designed to fit rows of cards in the drawers of an IKEA 9-Drawer ALEX Unit (Like this one: https://www.ikea.com/us/en/p/alex-drawer-unit-with-9-drawers-black-brown-70483434/). The top 5 drawers fit 3 rows of cards using the horizontal storage trays, and the bottom 4 drawers fit 4 rows of cards using the vertical storage trays.

Credit to Zack Freedman for his EXCELLENT Gridfinity system!

Also credit to tinyfluffs for use of their Fusion360 model for the baseplate profile (https://www.printables.com/model/354514/files), and to ismann for his card storage tray inspiration (https://www.thingiverse.com/thing:4604341).