Masks do not replace social distancing. While DIY face masks may be useful in situations like grocery stores and pharmacies where you cannot always stay six feet away from people, masks should not be used as a replacement for social distancing.
And remember: By covering your face in public, you are helping others to stay safe from anything you may be carrying. It’s more about their protection than your own.
The three scarves tested ― made of merino wool, cashmere and lightweight ramie (similar to linen) ― all captured fewer than 10% of smallpox-sized particles. The worst scarf material – 100% ramie – filtered just 2.8%.
The best overall materials for DIY face masks
Based on a combination of breathability and filtration effectiveness, the study recommended denim, bed sheets (80-120 thread count), paper towels, canvas (0.4-0.5mm thick) and shop towels for homemade masks.
Keep in mind, however, that paper towels are not washable or reusable.
The 0.4-0.5mm thick canvas material ranked as being easier to breathe through than a surgical mask, while still performing fairly well at filtering particles. But if thick fabrics aren’t available to you, the study’s data showed that 100% cotton T-shirts, layered up, are also still effective options for homemade masks. (More on this below.)
In general, natural materials are a better option than synthetic ones. Because synthetic fibers (like polyester) tend to be smooth, they don’t filter out particles as well as the rougher texture of natural fibers (like 100% cotton).
Best materials for blocking small-size particles
For 0.3-micron particles, Smart Air found “a much wider range in effectiveness.” The N95 mask, HEPA filter and surgical mask performed best, all capturing over 75% of small particles. But in terms of household materials, the best blockers were Hero-brand coffee filters. In the study, only four other materials filtered more than 48% of small particles: the 40D nylon, Chemex coffee filter, kitchen towel and canvas.