Earlier quoted context omitted.
> A cloth mask will not protect you against an aerosol "In unpublished work, Linsey Marr, an environmental engineer at Virginia Tech in Blacksburg, and her colleagues found that even a cotton T-shirt can block half of inhaled aerosols and almost 80% of exhaled aerosols measuring 2 µm across. Once you get to aerosols of 4–5 µm, almost any fabric can block more than 80% in both directions, she says." "Benn worked with…
On the other hand some researchers think cloth masks, specifically gaiter types, are worse than nothing. https://advances.sciencemag.org/content/6/36/eabd3083 > A bigger droplet scatters more light than a smaller droplet. This insight is important to interpret the result of the neck gaiter. The neck gaiter has a larger transmission (110%; see Fig. 3A) than the control trial. We attribute this increase to the neck gai…
The only mask that was worse than nothing was the Neck Gaiter, but the difference was both clinically small as well as statistically insignificant.