Use this to hold your filament in a classy, minimalist way! Works with virtually any diameter of filament spool, useful for odd sized rolls.
Note: I would recommend placing this so that the roll of filament is braced against something, as shown in the photo so that it does not get pulled off by the force of the filament.
I wanted to print this part: http://www.thingiverse.com/thing:335778 but I had no ball bearings. I did my best to reverse engineer it and made this. There are slots for using 3mm Ninjaflex filament to make it grippy, however these slots are untested thus far. If you print this and have access to Ninjaflex, please comment with whether it works or not.
Modeled in Blender