Date Time Proper fit of face masks is more important than material, study suggests A team of researchers studying the effectiveness of different types of face masks has found that in order to provide the best protection against COVID-19, the fit of a mask is as important, or more important, than the material it is made of. Fitting the face perfectly is a difficult technical challenge and small differences, such as a centimetre wider nose or slightly fuller cheeks, can make or break the fit of a mask Eugenia O’Kelly The researchers, from the University of Cambridge, carried out a series of different fit tests, and found that when a high-performance mask – such as an N95, KN95 or FFP2 mask – is not properly fitted, it performs no better than a cloth mask. Minor differences in facial features, such as the amount of fat under the skin, make significant differences in how well a mask fits.