Health authorities are now recommending that masks be worn to cover the nose and mouth, if you must venture out in public, but manufactured masks are difficult to come by. Consequently, many are making their own masks.
This Washington Post story notes the most effective homemade masks are made from cotton, specifically “tightly woven” cotton of 180 thread count, or higher—think of bedsheets or pillowcases. Cotton t-shirt material can also be effective. The key is to layer the fabric, the experts say, and be sure to wash your mask immediately after wearing it.
One of the studies referred to in that story is here.
And then there’s this reference.
Cotton is not only comfortable, it can be a lifesaver.