TORONTO -- With more people fashioning their own homemade face masks to prevent the spread of new coronavirus, researchers in the U.S. have found that wrapping nylon stockings around the face coverings can make them considerably more protective.

In a study that has not yet been peer-reviewed, but has been published on the scientific preprint site medRxiv, researchers from the University of Northeastern University in Boston show how nylon stockings filter out small particles in the air by creating a tighter seal around the homemade face mask.

“Adding a layer of nylon stocking over the masks minimized the flow of air around the edges of the masks and improved particle filtration efficiency for all masks,” the authors wrote in the study.

The nylon outer layer was able to increase the filtering capability of homemade cloth masks to match or even exceed that of medical-grade surgical masks; however, not the in-demand N95 respirators.

The study’s authors said the added protective layer could be an easy, affordable way for people to boost the protectiveness of homemade masks for the wearer themselves.

Previously, public health officials have warned that homemade fabric or cloth face masks can be worn to protect others in the community, but they’re not considered protective for the wearer.

While the academics said more research is needed, they said the forward-looking intent of the study is to “optimize health protection given resources at hand.”

As researchers explore new methods to increase the protectiveness of homemade face masks, has rounded up some other dos and don’ts to keep in mind when it comes to face coverings in the time of COVID-19.


Do wear out in public

Public health officials have recommended that people wear homemade face masks when they’re out in public, especially when physical distancing may be difficult, such as in grocery stores and or on public transit.

This is to protect others around the wearer because there is evidence the virus can be spread among asymptomatic individuals, or those who don’t have any symptoms of COVID-19.

Do use tightly woven materials

Homemade face masks that are made out of tightly woven material fabric, such as cotton or linen, will be more effective at preventing the spread of the virus, according to the Public Health Agency of Canada (PHAC).

The health agency recommends that masks be made of at least two layers of fabric. They will also be more beneficial if a paper towel or coffee filter is put inside a sewn-in pocket on the mask.

Do ensure it fits snugly

Canadian public health officials said homemade face masks should be large enough to completely cover the wearer’s nose and mouth “without gaping.” The face masks should fit securely to the head and sides of the face with ties or loops over the ears, but still allow for easy breathing.

Do wash it regularly

According to the PHAC, face masks should be regularly machine-washed in a hot cycle. However, for the mask to be effective, it shouldn’t lose its shape after washing and drying.

If it does, wearers should consider making another face mask with materials that won’t become distorted in the wash.


Don’t adjust it or touch it often

Homemade face masks should be comfortable enough so the wearer doesn’t have to frequently adjust or touch it, according to PHAC.

Health officials warn the wearer might infect themselves with the virus if their hands are often touching their face to adjust the mask.

Don’t share your mask

Public health officials stress that homemade face masks should be made for individual use and they should not be shared, not even among those in the same household.

The masks should also not be reused by the original wearer if they become damp or dirty, PHAC said.

Don’t put one on a child under the age of 2

Children under the age of two should not wear homemade face masks, public health officials have stressed.

Face masks should also not be worn by individuals who have trouble breathing or difficulty removing one without assistance.

Don’t substitute a mask for other precautions

While homemade face masks can help to prevent the spread of virus in communities, public health officials said they should not be used as a substitute for other preventative measures, such as hand-washing and physical distancing.

“No mask will ever replace physical distancing. We want to emphasize that all of the recommendations regarding staying home, physical distancing, and hand hygiene are based on what we know will work best to protect you and your family from infection,” PHAC states on its website.