You should be wearing a high-quality mask when you run errands, go shopping or find yourself in a situation where you’re spending time indoors with people who don’t live with you, Dr. Marr said. “I am now wearing my best mask when I go to the grocery store,” she said. “The last thing I want to do is get Covid-19 in the month before I get vaccinated.”
Dr. Marr’s lab recently tested 11 mask materials and found that the right cloth mask, properly fitted, does a good job of filtering viral particles of the size most likely to cause infection. The best mask has three layers — two cloth layers with a filter sandwiched in between. Masks should be fitted around the bridge of the nose and made of flexible material to reduce gaps.
Read more at:
https://www.nytimes.com/2021/01/19/well/live/covid-b117-variant-advice.html