MasterSpool slim (<200mm width)

You might also want to check out these (didn't print those yet, but they might be better than my design):

https://www.thingiverse.com/thing:2885697
https://www.thingiverse.com/thing:2893005

For people with less space than a "standard" printing bed (smaller than 220 x 220 mm).

I have a 20 x 30 cm bed, so I cut some material off left and right. This is the remix.

*NOTE: filament tends to slide off easily when the spool is NOT in use. However, this is less likely while printing.*