Here is a simple printable spool rack. Can be adapted for any number of spools. The rack can be stacked for a low footprint storage solution.

20mm wooden dowel used for the spool storage rack.

Update: 12.01.22

New version added with 22mm holes.

Update: 30.03.22

New version added with 30mm holes. Warning: It is unknown if this version will print correctly / still be stackable.

Update: 10.23

New version added with 24mm holes