A video visualization created by NIST engineer Matthew Staymates shows how air flows with and without a face mask.

Staymates wrote in a NIST blog that “even the simplest face coverings…stopped...your cough from landing on someone else.”

Staymates: "...pulling your face covering below your nose is not good..."

Staymates: "...fabrics with very tight and nonporous weaves actually increase air leaking out by the nose and chin."

Staymates: "My hope is that the video...provides a helpful illustration for why we all should cover up..."