This is a custom organizer made for a friend of mine that holds file folders of varying thicknesses. The body is made from Thick Draftboard, and the removable, E-shaped dividers are done in Medium Draftboard. Fully populated, it’s made to hold up to a dozen folders of 1/4" thickness. It will get some kind of surface treatment the next time I have leftover paint from a project.
Internally, the folders sit on a raked floor which is suspended from the sides of the box. The angle is set to ensure that each folder is a half-inch higher than the one below it so the folder tabs will always be visible.
The dividers fit into a comb-shaped piece mounted between the side walls and the floor. I kept the interface between the comb and the dividers flush since I don’t expect the dividers to move very often and they need to stay put when removing a file folder. The fingers of the comb are glued to the wall since they’re fairly thin, although the base of the comb has slots for tabs on the floor.
The central leg of the divider extends through a slot in the floor, which holds the leg securely, but a 5-thousandths clearance keeps it from requiring too much force to insert.
I love projects when I can optimize the cut sheet 
