Enough time has past since the pandemic began that scientists are evaluating the protective levels of cloth masks down to the nitty-gritty. Is a cotton mask better than one made from cotton and silk? What about thin, cloth-made masks vs thick ones? How do they rank in the current collection of protective face wear?

Some experts say this, others say that. But, all agree on one thing, which we'll discuss in a second.

Scott Gottlieb, MD, is not a fan of cloth face masks. Last Sunday on "Face the Nation", Dr. Gottlieb, former commissioner of the US. Food and Drug Administration (FDA), said many other types of protective face gear, like the N95 mask or the FFP2, can provide 90% to 95% protection. He said that cloth masks, at most, offer 30% protection.

But, that percentage of efficacy can go up if the mask has padding that isn't totally made from cotton. Thickness matters, Dr. Gottlieb said. And, if the mask is made from a cotton-polyester blend, so much the better.

Similar, But Slightly Different, Viewpoints

In a recent study of their effectiveness, Stephen Salter, a mechanical engineer and president of Farallon Consultants Ltd, in Victoria, British Columbia, found that cloth masks can play an important role in reducing the spread of COVID-19 -- and they are cost effective.

Masks are necessary to block respiratory droplets that people expel while coughing, sneezing and talking. These droplets remain suspended in the air for a considerable time, depending on the environment. Mr. Salter’s study showed that face masks made from various materials, including cotton, are 70% to 90% effective. But the fabric does make a difference.

Loosely woven fabrics have larger spaces between the threads than tightly woven ones. However, adding a layer of batting, such as that used in quilting, adds extra protection.

The researchers put 17 handmade cotton batting masks through 35 tests to check for filtering effectiveness.

Although these masks were thicker when made with batting (between 3.7 and 7 millimeters), they were 76% to 90% effective in filtering aerosols.

However, the researchers did point out that proper fit is important as well. Masks are sold as a one size fits all, but that’s not really the case. Some may need bigger masks to cover their nose and mouth properly.

Another study published in the ACS Nano, a journal of the American Chemical Society, had similar conclusions. The researchers tested common fabrics in masks, using different combinations, such as cotton and silk, cotton and chiffon, and cotton and flannel. The bottom line was that multiple layers of fabrics boosted the filtration of cloth masks.

Why You Need Face Masks

The agreed-to point: It's important thing is to wear a mask. Dr. Gottlieb recommended a national mask mandate to slow the spread of the virus, adding that the mandate doesn’t need to be backed up with penalties or strict enforcement.

“We have a moment of opportunity right now to take some forceful steps to try to abate the spread that's underway. But if we don't do that, if we miss this window, this is going to continue to accelerate and it's going to be more difficult to get under control,” he said .

The US Centers for Disease Control and Prevention supports using face masks to reduce the chance of spraying, or catching, liquid droplets when people cough, sneeze or speak. They are a physical barrier. When you combine masks with physical distancing, your odds of getting COVID-19 are lower, compared to those who do not follow safety guidelines.

Will we need masks once a vaccine against the virus is available? Dr. Gottlieb said that even if a vaccine is approved and distributed, it is most likely the elderly and healthcare workers will get the first round. "They’re not going to have protective immunity until 2021,” he said. It also takes time to build up immunity, even after a vaccine. “So this vaccine is not going to affect the contours of what … is going to play out in the next two or three months.”

The Take Home

Cloth masks may lower COVID-19 transmission. They also help with your tight budget. Experts are concerned that people wear their masks properly and wash them after use. You can wash cloth masks by hand or washing machine, using detergent and the warmest water possible.

Whether you choose a disposable surgical mask or a cloth mask, always check the fit. The mask must cover your face and nose, and go below the chin and across your cheeks. Masks not worn properly will have no effect.