you’re welcome. i’m a bit low on sleep so i missed part of your question, and don’t think the video addresses it — that is, are two [cotton] masks more effective than one. i honestly think that this is an interesting question. for most people, their intuition would be to answer “probably,” but i suspect there are some complexities that someone smarter than i am would have to address.

wearing two masks instead of one wouldn’t make things worse, though. but better? again, good question.