For breathability, there is no escaping physics. All N95s outperformed #1 and #2 despite having thicker/better filters because the formed shape allows more of the mask surface to be used, whereas #1 and #2 pulled into my nose and mouth, reducing the usable mask surface to the size of my open mouth. Pairing #1 or #2 with a #3 or #4 mask stand made breathability excellent, and even here the larger surface area of the proof-of-concept (#3) had an edge. Physics.
For glasses, the only ‘5’ is #8 because it directs all exhaled breath away, and the rubber nose bridge provides a place for glasses to securely rest. Bendable metal nose bridge pieces (#2, #6, #7) reduced glasses fogging, but needed periodic resetting (constantly with #2). The foam under the nose bridge of #6 helped reduce fogging further. #3 and #4 also didn’t fog glasses because the hard frame prevented exhales from going toward glasses, but the frame interfered with seating.
Wearability is clear cut. Minimize face contact, contact the face with fabric, and reduce excess bulk. Attachment with a band or bands is more comfortable than earloops (hello again, physics), and easy adjustability addresses swim goggle headache.
Also, growing stuffiness with #8 was surprising (heavy breathing started at ‘4’ and reduced to ‘3’). The check valves keep air moving through, but heavy breathing builds up moisture as it overwhelms the exhalation valve’s ability to remove it. I suspect when people complain about air in masks, it’s actually that retained moisture and higher humidity.
Beyond baseline safety, mask designs should:
Not all recommendations can be optimized without introducing manufacturing or sizing complexity, but each warrants consideration. My personal ideal for everyday non-exercising use would be a larger #6 with #1 or #2 material, and of commercially available options, the KF94 with an added ear saver would top my list.
Also, I recognize that my focus here for exploring facemask improvements has been to reduce the pain points, and the best case scenario with this goal is to get back to zero. And to that end, I’ve omitted targets like a mouth window for lip reading / emoting. I’ll be revisiting this from the human aspect, because that warrants at least as much consideration in making things better. Stay tuned.