Pinging @DukeTrout, @aLynHall, @NukeML, @d_r, @subextraordinaire, @gatto, @Ratel, and basically everyone who is going to have people asking them about masks because of the recent “gaiters/masks” thing.
HTH.
It does have a bloody ‘shopping list’, and just look at the time it was published…
Another detail I haven’t seen mentioned is air space inside the mask. Like I said before, I have seen both rigid and supple N95 masks. With the rigid, you have a distance between your mouth and the mask.
I think that would be important. Imagine spitting through fabric stretched tight across your mouth, and then spitting through fabric held out away from your mouth. The gaiter they tested was probably tight across the face. One that was more loose would probably block more, even if it was the same fabric.
Although it needs to be snug enough around the edges that you don’t simply have unimpeded airflow all around.
Hmm. I’ve been using a bandana as a mask, but it’s not a bandito-bandana; the way I fold it, it’s six layers thick, and it’s held pretty snugly in place by rubber bands around my ears. It’s not just folded diagonally and tied behind my head, which would be worthless. (I learnt to do that as an improvised surgical mask during my decades-obsolete wilderness-first-responder training.)
I’ve switched to manufactured cotton face masks, even though I believe they’re less effective than what I’ve been doing, because the popular misreading of this paper has led my local leaders to ban bandanas as face coverings, however worn - and I believe that would extend to a mask sewn from the bandana’s material, because of course the ‘bandana-ness’ will propagate. The paisley print destroys the cotton’s effectiveness, you know!
Leakage around the bridge of the nose is a pretty significant thing. For the bandana-masks, I can work around that again with how they’re folded, because there’s enough fabric that bunches against my cheeks that my classes don’t fog when I’m wearing them. Leakage would be more of a problem with a sewn mask from the same material unless I worked out how to put some sort of stiffener across the top edge to hold it tight on either side of my substantial beak.
From what I know of physics, pore size on the fabric is much less important than tortuosity of the air path and hydrophilicity of the material. Basically, you want to expose the air stream to as much surface area as possible of a hydrophilic surface, to give droplets the greatest possible chance to adsorb.
The cotton + poly or cotton + silk thing is interesting. It stands to reason that if you can charge droplets up electrostatically and then expose them to a surface that’s got the opposite charge, you can precipitate them better.
The jury is out on big droplets vs small droplets. Big ones settle out faster, but small ones evaporate faster, and desiccated virus appears not to be terribly infective. Partly evaporated big droplets are likely the worst, because the virus is still wet, and you’ve concentrated it by evaporating away the water.
Yes, I saw a delivery person with a gaiter that had elastic at the top, but the fabric itself was not all that stretchy, and hung loose. Seemed to be a decent fit at the top, and gathered down at the neck. Looking at it, i had the feeling if he sneezed, it would inflate like a balloon and not much would get out.
Everybody, get your flu shot if you can safely do so.
I’ve used this method, too. (And you can add a coffee filter with this method, too.) My guess is that they were looking at double layer bandanas, bandit style.
I also use my sunglasses to create a seal around my nose. And the bottom of the glasses help push the fabric flush against my upper cheeks.
Most importantly, we stay far, far away from everyone who does not live with us and move quickly through the grocery store. (No other shopping or public areas for us, and we’re not as neighborly as we used to be. 
)
@LutherBlisset thanks for linking that paper!
Continuing with the WDKS chorus, covid is bad for hearts, but we don’t know how bad. If your kid gets sick, take 2 weeks off after the last of the symptoms resolve. Minimum. If your kid is hospitalized, probably need cariology clearance to return to organized sports.
THAT is bad. Time to contact your local news and set them straight!
@FGD135 re.: Philippines’ Duterte volunteers to be Putin’s coronavirus vaccine guinea pig…
The irony in all of this is probably exemplified by the RaDVac whitepaper (which I won’t link, but) which was reviewed by MIT’s Technology Review on July 29th. The RaDVac design is by apparently legitimate experts, more “Scientist Citizens” than “Citizen Scientists” and they eat their own proverbial dog food (N=70 apparently). The lab procedure appears to be straightforward, the ingredients also, excepting the protein snippits (which appear to be the sorts of things that are readily available, @docosc found the peptides for sale as well, and I’m sure an expert here will probably clarify are actually pretty easy to synthesize if you do that kind of thing for a living).
So good old 
scientific know-how has handed the world an expertly designed vaccine candidate which is probably at worst harmless, maybe someone will have a bad reaction to the peptide snippits, but which quite probably confers some unknown but likely significant degree of protection.
This is where a courageous, scientifically literate leader steps up, indemnifies the process, says “we’re looking for lots and lots of volunteers, me and my family first,” and “everyone keep the d*** masks on until we say otherwise”.
I’m no fan of the current occupants of any of the respective governments in question here. Although their approach is likely to lead to scientifically sloppy results, I think 
and 
will have this beaten before does and not really for the right reasons.
I assume the internal volume of the N95 masks makes breathing easier and prevents the feeling of suffocating. With all other types of masks, they actually should really cover your mouth and nose. If you have an internal volume, they will also allow gaps to form, which counters the purpose of the mask.
Ooh! Ooh! Ask me!
After Covid-19. As in, when Covid-19 is over. Unless your child has been permanently crippled. In that case, never. But then the team isn’t going to take them anyway.
by Cronkite News, Allison Barton
August 12, 2020
True story: I knew a guy who had to give up his upholstering career because the dust affected his lungs.
Wear your masks, kids.
DeSantis has instructed all FL schools to only switch completely to online if local health departments tell them to, and has further instructed all local health departments not to opine on this issue.
I am rapidly losing my opposition to the death penalty.
This article has the explanations of which masks are which in that latest news study.
The CNBC article seemed to lay out the finding better than the other linked articles, and that’s the version I’ve been pointing out to people. A lot of the articles I’ve seen gloss over the different types of masks tested, or present them in a confusing manner.
Hm, my first thought was:
