[This is a guest post by my partner Alexandra van Geel.] TL;DR Hello everyone! The Basics: Masks vs. Respirators Question: What makes a good mask? Commercially available options The O2 Canada Curve Respirator The Vogmask valveless mask Some tips about comfort References Disclaimer: I am not an expert, just a private individual summarizing available information. Please correct me if I’ve gotten something wrong. TL;DR I suggest: (a) the Vogmask valveless mask or (b) the O2 Canada Curve Respirator.