My wife and I hate having to fight the little bag that cotton rounds come in. So I took it upon myself to whip something up. The inner diameter is 68mm so it should fit most standard cotton rounds. If for some reason this doesn't work for you or if you need another size just leave a comment and let me know.
Bill of materials:
About 35 gram of filament. Roughly $.90 to print.
Printing:
Nothing of note here.
Infill: 10%
Assembly:
Place cotton rounds inside finished print.
The author marked this model as their own original creation.