Rack to store your filament spools.
The cleats are fitted with 4mm countersunk screws, 2x per cleat, the cleats are 20mm thick. In the image I attached the rack to a plasterboard so used countersunk m4x50mm bolts, secured in metal expansion plugs. 1 cleat per 1m, but depends on the rods and how sturdy your wall is.
The racks are connected with 21mm wooden rod, was the easiest and cheapest for me to obtain, can easily be modified in the .f3d file if you got other rods. The rods can be fastened in the racks with 3x25mm countersunk wood screws.
Printed the cleats in PA-CF and the racks with PETG, might be a bit overkill though. Depends on how you decide to set it all up! But probably want a lot of walls and a lot of infill.