FABRICS FOR FACE MASKS
The best face masks has three layers; one to wick moisture from the face, a middle layer to filter and and outer that is hydrophobic ie. it repels moisture. This is similar to the construction of the medical N95 respirators.
There are many fabulous patterns out there freely available or at a modest price. The one we use at home is the Olsen mask by sewcanshe.
Note, if you are making a pleated mask then you are probably only going to use two layers as having the filter layer makes it too thick to sew.