By Bonnie Berkowitz and
Aaron Steckelberg
 
Are you a medical professional?
Can
you
sew?
NO
NO
YES
YES
Use N95 or surgical masks
Sew a cloth mask
Cut a cloth mask
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On April 3, U.S. health officials recommended an arts-and-crafts project to U.S. residents: Make a cloth mask, then wear it when you go out in public.
Covering your mouth and nose is one more thing people can do in addition to social distancing and hand-washing to slow the spread of the novel coronavirus, according to the Centers for Disease Control and Prevention. Medical-grade masks are scarce and should be reserved for front-line health-care workers who are repeatedly exposed to huge amounts of the virus.
But a DIY face cover offers a bit of protection to the wearer while helping prevent them from unknowingly spreading the virus to others, a useful thing when up to a quarter of people who have covid-19 may show no symptoms, according to the CDC.

I’m in. What material should I use?

The coronavirus is extremely tiny — too tiny to be trapped by most fabrics that still allow air to flow through them.
Coronavirus
E. coli bacteria
Human
red blood cell
0.1 micrometer
average
diameter
2 micrometers long
7.5 micrometer
diameter
However, the virus seems to be most transmissible when it is stuck to much larger water or mucus droplets that come out of our mouths and noses when we cough, sneeze or talk, and a homemade mask can block those dropletsAs the mask needs to be made of something you already have around the house, cotton seems to be a good choice. The CDC recommends two layers of tightly woven 100 percent cotton fabric, such as quilter’s material or bedsheets with a high thread count.
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A group of scientists and doctors at Wake Forest University tested different masks made by community volunteers and found two of the better options to be a double layer of cotton with a thread count of at least 180, and a double layer of normal cotton with a layer of flannel in between.
Speaking of layers, don’t just pile them on. You need to strike a balance between breathability and filtration.
Make sure you can breathe comfortably through your nose while wearing the mask — sticky nose hairs can catch some particles as well before they travel deeper into your respiratory tract. If the mask isn’t porous enough, you will be breathing around the sides of it rather than through it.