The Big Mask Update – Part 1

A sewist perspective on mask misinformation, 3-layer masks, filter pockets, new government recommendations, and other matters of safety

By Kitty

DISCLAIMER: As always, nothing in this article is meant to be official medical or safety advice.  Everything presented here is either publicly available information that’s considered accurate at the time of writing, or just my opinion.  If you have health-related questions regarding the pandemic (or anything else), you should seek answers from your health care professional, not a sewing lady off the internet.

NOTE: Most of the masks we’ve been making for sale and donation have been two-layered to date, because that’s what the official guidelines recommended at the time.  Obviously, we’re changing that.  In the meantime, you don’t need to toss out your old masks; I’ll be posting a tutorial shortly on how to retro-fit a makeshift filter pocket on them.


In the past week or two, the Canadian government has dropped some new official recommendations regarding face masks and COVID-19.  I’m not repeating all that info here, since you can get it straight from the source (and you should). 

But I thought I’d summarize some ideas that are most relevant to us regular folks, and also call your attention to some misinformation which has been making the rounds.  Some of the false claims are just silly, but others are downright hazardous, so it’s worth educating yourself.  So here’s an info-heavy, no-pictures, not-fun-but-relevant article that’s worth one read-through.

Despite what you may have heard, seen on shelves, or read on the internet…

1. Virus-Proof Masks?

No mask is virus-proof, self-sterilizing, prevents microbe growth, or any of those things that just don’t science.  I even saw one brand of mask that claimed that it used “sterilizing ultraviolet rays” to keep you from catching viruses (oh, I really hope we’re all too smart to fall for that). 

ABSOLUTELY NO MASK you buy (except N95 masks, sort of) can offer you a guarantee that it will prevent viral infection.  It’s actually kinda illegal to say it can.

2. Alternate Materials?

None of the following materials have been tested for effectiveness in face masks in real-life conditions.  This doesn’t mean they don’t work, just that they haven’t been put through proper robust scientific studies, so we just can’t know.  A material that works great in itself may be totally inappropriate for use in face masks.

Some of these may be proven effective in the future, and some are even currently recommended, in the absence of more data.  Others are just plain rubbish or even dangerous (I’ll go into a bit more detail on which, how and why on Part 2 of this series).

  • Paper towels, blue shop towels, facial tissues, newsprint, other paper products
  • Coffee filters, dryer sheets, microfibre tea towels, or other household materials
  • Baby wipes or sanitary napkins
  • HEPA filters, air purifier filters, air filtration system filters, vacuum cleaner bags (HEPA or otherwise)
  • Interfacing, craft batting, polypropylene non-woven fabric, felt, other craft fabrics
  • GORE-TEX fabric, tent material, and other rain-gear materials
  • Halyard H600 medical-grade sterilization wrap material, which I have high hopes will be proven to work at some point in the future.  But I’ve not been able to find any evidence at this moment that it’s any good for sewn face masks.

3. Reusable Filters?

A lot of available reusable filters are a bit questionable.  Most, if not all, of them have never been tested to see how they hold up over multiple washings, and some of them apparently totally disintegrate after being put through a hot wash-and-dry cycle or two.  So be careful and use your judgment if you’re relying on these.

4. Ventilator Buttons?

Masks with ventilator buttons/exhalation vents/breathing vents are basically useless.  Unless they’re plugged up with some kind of filter, in which case, what’s the point of having a vent in the first place?  Vent openings are not really different in principle from just punching holes in your mask.  This isn’t just my opinion, by the way; Canadian health authorities says much the same thing.

5. Best Material vs. Worst Fit?

It’s a myth that the most important thing about a mask is what it’s made of.  Even masks made from the very best medical-grade materials are worth squat if they don’t seal well against your face at the edges.  That makes sense; a virus or droplet doesn’t need to do the limbo through the tangle of mask fabric fibres if it can just shoot through the big gap at the sides or bottom of your mask!  Like water, electricity, and white-tailed deer, infectious particles often take the path of least resistance.

Actual government recommendations regarding masks, summarized

  • You should wear one anytime you’re in public, unless you have a valid medical reason not to
  • Your mask should consist of at least three layers of tight-woven, BREATHABLE fabric and/or have a pocket for a disposable filter
  • Masks should fit well, and stay close to the face at the edges, without any gaping
  • Your nose, mouth and chin should be covered by your mask
  • You need to change masks as soon as possible when they get wet or dirty
  • Mask materials should maintain their shape and structure after washing and drying (more on this oft-overlooked point later)
  • Choose reusable (not disposable) masks if possible

What NOT to do, simplified official Government of Canada version

  • Never uncover your nose or mouth, or hang your mask from your ear or off your chin (you know you’ve seen people doing this!  Don’t be one of them.)
  • Avoid masks with those “ventilation valves” (also called exhalation valves or ventilation buttons) or made from loose-weave materials or with holes
  • Don’t use materials that fall apart, like tissues
  • Don’t use non-breathable materials
  • Don’t put masks on anyone who can’t safely remove it themselves if it becomes necessary
  • Don’t put a mask on anyone who’d having trouble breathing
  • Don’t put masks on children under 2 years
  • Don’t choose masks that impair your vision or interfere with something you’re doing
  • Don’t share masks

Who SHOULDN’T wear masks?

  • Children under 2 years of age
  • Unsupervised children between age 2 and 5
  • People with health conditions that may be made worse by wearing masks
  • People who can’t easily remove masks if needed

What about face shields or those neck gaiter thingies?

Face shields don’t replace masks, though they do protect your eyes from flying droplets.  Because face shields don’t prevent droplets from entering or escaping through the open sides and bottom, they don’t protect you or others from spreading infection. You should only consider a face shield instead of a face mask if you’re unable to wear a mask for some reason.  You can wear both, of course.

Neck gaiters aren’t a good idea because they tend to slip around and need lots of adjusting (you shouldn’t touch any face covering while you’re wearing it, ideally), and because they’re hard to remove without contaminating yourself.  Again, you should consider them only if you can’t wear a face mask.

What should you look for in a reusable face mask (as per current new guidelines)?

1. It Fits *You*

It should fit YOU well.  Not your sister or boss or the model on the box.  This is probably the most-often-overlooked, yet perhaps the most important, factor in your hunt for the best face mask.  If there are visible gaps between the edges of the mask and your face, it doesn’t matter how great the mask material is, or how durable, or even how comfortable (yes, a mask can be comfy AND gappy at the same time).  It’s still an open door for infectious droplets to waltz in and out. 

So if you buy those one-shape-fits-all ten-pack masks, do the world (and yourself) a favour and check all around the edges in a mirror to make sure it’s conforming well to your face.  Do this after you’ve been wearing the mask for your daily activities for an hour or two, not right after you’ve put it on and adjusted it to perfection!

2. Minimum Materials

Masks should be made from at least 3 layers of breathable, washable, tight-woven (or non-woven, in some cases) fabrics that will hold up to repeated washing and drying (or at least 2 layers plus a pocket for holding disposable filters).  Since you should wash all masks after every wear, this is really important.  Also, any material that falls apart, frays, changes size, or loosens its weave after washing isn’t suitable for non-disposable masks.  Watch out for cheaply made masks with unfinished exposed seams, since fraying can lead to loss of protection.

3. Official Middle Layer Material

The official government suggestion is for the middle layer of the recommended three to be made from a non-woven polypropylene material (though they say another layer of tight-woven fabric is okay).  Buuuuuut….

4. The Professional Fabric Perspective

Here’s my professional fabric worker’s perspective on the above: most of those polypropylene non-woven fabrics tend to lose structural integrity much faster than, say, tight-woven cotton or linen.  If the middle layer is sandwiched between the two outer layers like the government suggests, how do you know if it’s disintegrating on you? 

Personally, I’d stick with another layer of tight-woven washable fabric for the middle layer. OR, if you want to use a reusable filter, opt for a filter pocket so you can see the non-woven polypropylene filter and change it when it starts to get manky.

5. Comfortable

It should be comfortable.  Every time you touch your mask while it’s on your face, you’re potentially introducing pathogens.  If you’re constantly adjusting your mask, you really need to try another fit, size, or style.  Not all styles work for all people, so it’s important to try different ones until you find one that works for you (you can always sterilize and donate the ones that didn’t work for you to your local shelter; someone in need will thank you).

Next Time, in Part 2:

Great-Aunty Kitty weighs in on assorted mask fabrics, filter materials, filter pockets, different mask design concepts for different faces and needs, and the who-why-how-when of each one.  And also, at some point before or after that, what you could do with all those two-layer masks you already have.

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