They are made of three non-woven fabric layers with the middle made of melt-blown non-woven fabric. As a cover, we’d suggest layering them with these double-layer 100 percent cotton masks from Vida.

A fabric face covering can be worn over your disposable medical mask to help prevent you from spreading Covid-19. Here's how to make one of your own.

Fragment of a blue and white, cotton and wool, double woven coverlet, with an Irish chain design. The donor, Mrs. Laura M. Allen, was Director of Weaving in Mechanics' Institute, Rochester, N.Y.