Not many people use paper anymore, but many still have file cabinets. Those cabinets are not well designed for random stuff.
Here are a few types of stackable organizers. They fit the two different cabinets I have, but double check the measurements before you print. If you need to make changes, I have included the parametric Solidworks files.
There are two sets of files included, one for smaller printers, one for larger.
Works well for printers with bed sizes of ~250mm.

Works well for printers with bed sizes > 300mm.

Because of the stackable feature, the bottom requires a little support material.
Turn on support material in the slicer.
Enjoy!
The author marked this model as their own original creation.