Double-masking, knotting-and-tucking for snug fit reduces COVID-19 spread, study shows

Results from one experiment demonstrated that the un-knotted medical procedure mask alone blocked 42.0% of the particles from a simulated cough, and the cloth mask alone blocked 44.3%. The double mask combination blocked 92.5% of the cough particles.
Source: https://www.bemidjipioneer.com