1. THE FABRICS MATTER While you see mask in all colours and shapes, what is important is that the 3 layers (no more than that please!!!) consist of materials which have the following characteristics:
1) Inner layer of a hydrophilic material
2) Middle hydrophobic layer of synthetic non-woven material - enhances filtration
3) Outer layer made of hydrophobic material - helps limit external contamination
Check out this NST article or this World Health Organization (WHO) document!