Beside fitting nicely as a tall base for the Storage Hutch, this has turned into a great little storage drawer on my craft table (see the photo with paperclips).
Laser-cut heavy chipboard. Ships flat but a breeze to put together with the slots and tabs precut (you'll just need to secure with a bit of white glue).
Finished size is 4" wide x 3" tall x 2-1/2" deep.
Note: Items cut from this heavy, light-grey chipboard burn easily so the laser-cutting process may leave charcoal residue behind. Save yourself a headache, and just wipe the cut edges of these items down with a dry paper towel before assembling or painting.