In [comment #43 on this thread](https://forum.azimuthproject.org/discussion/comment/21974/#Comment_21974) you cited a web page on how to make a DIY mask out of paper towel and rubber bands.

I did a quick Google search on making DIY masks, and found [this survey](https://smartairfilters.com/en/blog/best-materials-make-diy-face-mask-virus/).

Not sure how authoritative this is, but it's something, and presents some concepts to consider. Cotton T-shirt was one of them. Paper towel not mentioned. A good advantage of paper towel of course it it's disposability.

Perhaps paper towel -- two layers? -- could get upvoted, on account of the significance of large droplet size?