What are the Best Materials for a Mask?

Wearing a mask is an essential part of maintaining public health and stopping the spread of the coronavirus (COVID-19). There's plenty of tutorials that explain how to make a mask at home. But it leaves you asking questions like, "What material should I use to make a mask?" Or "Can I just use an old t-shirt?"

man wearing a mask out in public

Don't worry! We're going to tell you the best material and what you should look for in your mask.

N95 masks and cloth masks

First things first: If you need a mask, the CDC recommends you purchase a cloth one to keep the N95 masks for medical personnel battling COVID-19.

The best materials for cloth masks

girl wearing cotton mask

Let's take a look at what type of material should be used if you're making or buying a mask.

The Argonne National Laboratory and the University of Chicago tested a variety of common materials to find which was the best at stopping the coronavirus. 

Their research covered common fabrics including cotton, silk, chiffon, flannel, various synthetics, and their combinations.

The researchers found that multiple layers of mixed fabric was the best way to filter the virus particles. "Overall, we find that combinations of various commonly available fabrics used in cloth masks can potentially provide significant protection against the transmission of aerosol particles."

The most effective mask is one that is made of multiple layers of high-thread-count cotton fabric. It helps to have one to two layers made of a cotton/spandex mix to improve the fit of the mask.

The best fit for cloth masks

a cotton mask that fits well

If a mask doesn't fit properly or is worn incorrectly it becomes almost useless. After testing the various material, the researchers poked holes in the fabrics they were testing, to mimic a mask with gaps.

"Our studies also imply that gaps (as caused by an improper fit of the mask) can result in over a 60 percent decrease in the filtration efficiency," the researchers explained.

In addition to choosing your fabric, make sure that your mask fits well, and to wear it properly. Gaps between your face and the mask will make it ineffective,

Material testing for masks

They used an aerosol mixing chamber to determine the effectiveness of the materials. The research team passed the particles through each of the fabrics and sampled the air that made it through the material.

Aerosol Mixing Chamber

(Konda et al., ACS Nano, 2020)

They tested particles as small as 10 nanometres up to 10 micrometers (a human hair is approximately 50 micrometers in diameter, and there are 1000 nanometres in a micrometer). Coronavirus particles are between 80 and 120 nanometres in diameter.

The most effective mask

When purchasing or making your mask, it should cover three factors to be an effective mask: proper fit, proper materials, and multiple layers.

A mask that doesn't fit correctly is useless in protecting you from microparticles. And having multiple layers of fabric, such as cotton, will help improve filtration efficiency.