My search for the perfect mask to fit my personal requirements, trying them all out so you don't have to. Will keep updating this post as I go. CAVEAT: I am not a doctor or an epidemiologist. I am not an authority on this topic. If you're looking for a professional opinion on any of this, please exit the building now. This is just what I'm concluding from the firehose of info coming in. And as I find out more, or if I find I've got something wrong, I'll update this post. Expect what we know about the science of all this to change, because research is an ongoing process. All we can do is to operate on the best information we have at any given moment.

About risk:

COVID-19 appears to spread easiest through the air in a poorly ventilated inside space. (<--READ THIS very helpful document kept updated by aerosol scientists) So my level of risk in any given situation is:

  • ⏱ Time x
  • 📐 Size of space and/or amount of 💨 Ventilation x
  • 👬 Number of people x
  • % 😷 Mask users  x
  • 🤡 Behavior

     = RISK

Behavior is whether the people around me are shouting or singing or breathing hard through their mouths(like at a gym), and of course how close they are to me. But given enough time, sharing, say, a small stuffy office space with someone even 2 meters away means eventually probably inhaling some of what they exhale unless both people are wearing masks. Ventilation (how frequently the air around you is refreshed with fresh air, because the virus has been found to be airborne in aerosols) is also key.

So ideally I:

  • meet people outside at a distance
  • or in a well-ventilated inside (ideally with masks on)
  • or if I have to be in a not well-ventilated inside, masks on definitely.

I avoid:

  • events with lots of people inside without masks on

I also wash my hands and try not to touch my face. All of the above is pretty easy to do, and drops risk considerably. For winter, my first thought was that it's going to be a lonely time, and then I remembered that saying about there is no bad weather, only bad clothing, and figured what I should be doing is getting proper warm clothing that it will be nice to sit outside in. Anyway, on to the topic at hand:

About masks:

  • Literally anything in front of your face is better than nothing. (There is a study that concluded fleece masks are an exception, but it has been called into question because it was studying a testing method, not mask effectiveness.) If everyone wore some kind of face covering 100% of the time, infection rates would likely drop considerably. There also seems to be a correlation between viral load and how sick you get, so if a face covering simply cuts down on how many coronavirus particles get in your lungs, that already helps a lot.
  • Masks with exhale valves may protect you, but don't do much for the people around you.
  • Touching your mask a lot is not recommended, so try to only hold it from the ear loops, and wash your hands before touching it in general. Also keeping your mask in a paper or plastic baggie when you're not using it is recommended, presumably because it then does not pick up random particles in the environment as you walk around. To picture this in concrete terms in "normal people language": the outside of the mask theoretically gets covered in "glitter" as you walk around, and you don't want that glitter on or in you.
  • Masks lose a lot of their filtering effectiveness if they are not properly fitted to your face. Try to find a mask that fits your face size. Make sure it covers your nose, mouth and chin, and doesn't let most of the air leak in and out from the sides. Bend the nose wire to shape if it has one, place it evenly on your face, and adjust the straps so it's held there comfortably but firmly with as few gaps as possible. This being said, again, anything is better than nothing, so don't stress. (However, please don't dicknose. It's ridiculous. See illustration below.)
  • A VTT tutkimusprofessori said you shouldn't wear your mask for longer than 30 mins at a time, because after that it gets damp. Apparently damp masks are more likely to let droplets through. But by then they're pretty gross and you'll be likely to want to change to a fresh one anyway. If I'm heading out all day, I might bring more than one in individual baggies so I have the option to change if I have to use one for longer than I'd like. Also how fast they get damp depends on the materials used in the mask. An N95 is designed to be used for hours at a time, for example, and the DIY model described at the end of this post is also apparently pretty good with moisture.
  • There are different certifications for masks to describe their effectiveness. In Europe, we've got FFP (filtering facepiece) masks, which come in the following classifications:
Class Filter penetration limit (at 95 L/min air flow) Inward leakage non-EU equivalent
FFP1 Filters at least 80% of airborne particles <22%
FFP2 Filters at least 94% of airborne particles <8% N95 or KN95
FFP3 Filters at least 99% of airborne particles <2% N99 or KN99

The US uses NIOSH classifications. The ones relevant to COVID-19 are the N-class (N stands for not resistant to oil), and the number after the N refers to the efficiency level. The K in front of, say, KN95 means it's a Chinese standard but basically equivalent to N95, unless you have strict professional medical requirements.

Here's more info on how the actual filtering works, from USA Today. If you really want to geek out on all this, watch this video:

And see this excellent practical and straightforward mask info thread by Senja Larsen. Again, pretty much ANYTHING in front of your face is better than nothing.

Got all that? Let's come back down to the matter at hand.

My personal preferences in a mask:

  • Everyday washable easy on/off masks for low-risk errands like grocery shopping. Bonus for better filtration, but balanced with breathability.
  • Hardcore masks that seriously protect me as well as others if I have to be in an unventilated inside space with other people for a long time.
  • Noseclip in a cloth mask is a must in order to get a good fit. Unless it's a really clever design that I haven't come across yet.
  • Must be comfortable for all day use.
  • Would be great if I could easily talk, open my jaw, and smile while wearing these. The KN95 for example isn't great for this; the seal around my face breaks pretty easily if I open my mouth a little.

What I've found so far:

(In terms of what one can buy. DIY mask info is at the end of this post. Will keep updating this list as ordered masks arrive, so check back later.)

There are tons masks out there on the market right now, but I'm focusing on the ones that have some clear or unique filtration specs vs fashion considerations. I'll make an exception for particularly well-designed ones if I happen to come across any.

KN95 (95%)

KN95 mask

The trick with this thing is to bend the nose wire just right so no air blows up into your eyes as you breathe. I ended up not only bending it to my nose shape, but twisting the ends a bit towards me (corkscrew style), which worked really well. You'll also want to place it so it's snug against the rest of your face as well.

The ear loops are sometimes different lengths, so I put small knots in them if they were too long, but I've also heard a suggestion that you can twist them once to cross them and then put them over your ears to shorten them.

Once it fit right, it would collapse a bit on inhale but not blow air out anywhere (except maybe a bit to the sides) on exhale. Found it comfortable and not hard to breathe in.

However, these are expensive if you use them daily, not to mention disposeable. I'd rather not be generating this much trash. Would recommend for airline travel, however, where you may be seated beside dicknosing idiots for hours.

PacSafe ViralOff face mask (99% filtration efficiency)

Pacsafe Silver Ion face mask | Face masks | English
Pacsafe Silver Ion face mask, Pacsafe Silver ion Face Mask is a reusable and washable mask that provides at least 99% filtration efficiency against microbials and airborne particles. This mask is constructed with 5 different layers; each layer serves a specific function and ensures that the mask’…

This is my favorite so far of the cloth masks I've tried.

"reusable and washable mask that provides at least 99% filtration efficiency against microbials and airborne particles down to 2.5 microns (PM2.5), with a silver ion fabric that effectively disinfects and reduces microbes. Material: Silver ion cotton (main material) Modal graphene cotton (lining)"

Silver ion stuff may be a bit bullshit. Not sure how it affects viruses, but Coronavirus particles live on copper for hours.

I thought this might be good for an everyday mask that you only occasionally wear on and off. Available in three different sizes, where small fits kids, medium fits small adult faces, and large fits large adult faces.


Cleverly has not only a nose wire but a curved structural support that goes from nose to chin and helps keep the cloth from sticking to your face. Feels high quality, whatever that means. Includes ear loop adjustment tubes, which is excellent. There are black ones on the mask but also light gray ones in the package, presumably so if you have different sizes you can switch them out and see at a glance which is which. Ear loops themselves are both relatively thick and soft and just stretchy enough. All of this leaves the impression that this thing was pretty well thought out. Fits well on not only my face but on the faces of my family members as well. Feels pretty easy to smile and talk without it shifting massively out of place.

It is not, however, what I'd call "easy" to breathe through if you're breathing hard. If you breathe slowly, it's fine. This may be inevitable with masks, will update here if there's one that does this better.

One weird thing is the washing instructions are counter to what is generally recommended (warm water). Maybe because of the wool? I'm going to throw them in the laundry anyway and see what happens.

Totobobo mask (92%-99% depending on filter)

Singapore High tech PM2.5 air pollution respiratory mask
High tech pollution mask from Singapore. Best reusable protection against PM2.5 for whole family. Comfortable!

The above video is a pretty good overview of this thing, and I must say I rather like it. Looks a bit zombie apocalypse dystopian, but here we are. Small/medium size really seems like it's for children, large is for average to small-faced adults. It's reshapeable with hot water, and it's really easy to see if it fits properly or not. Has a wide range of filters available, and I find them quite easy to breathe through, and they have a "sports" filter that I haven't tried yet that I guess filters well but is MUCH easier to breathe through. They also seem to have gotten a head start in terms of tests of their masks, many of which are referenced here:

Someone else has also written up a very thorough review of Totobobo (and other masks) here.

Guzzini Eco Mask (95% filtering capacity)

ECO MASK, the reusable, eco-friendly protective mask. Produced in Italy using innovative plastic materials able to reduce bacteria proliferation.Eco Mask is extremely light, weighing just 45 grammes, and thanks to its soft, anatomically shaped sealing edge, it adheres to the face and fits all facia…
"innovative plastic materials able to reduce bacteria proliferation. Weighing just 45 grammes, and thanks to its soft, anatomically shaped sealing edge, adheres to the face and fits all facial forms snugly, with a level of comfort which allows it to be worn even for hours without itching, redness, marks on the skin, etc. With its special shape, one size man / woman, this mask can also be worn with glasses, with minimal lens misting. The large internal chamber, the well calculated filtration system size and the excellent fit ensured by the two configurations, behind the head or behind the ears, of the easily adjustable elastic straps, mean the wearer can breathe effectively without the unpleasant feeling of suffocation caused by many other masks. Fitted with an effective multi-layer fabric filter with a lifetime of 1 day and filtering capacity >= 95%, the Guzzini mask ensures a high degree of isolation from the surrounding environment thanks to the perfect seal between the soft, non-allergenic rubber edge and the face. What's more, the entire mask and straps are made from an innovative plastic able to reduce bacteria proliferation, minimising the contamination hazard. The Eco Mask has received CE marking as a Type I Class I (non-sterile) medical device under the EN 14683 - ISO 10993 standards and Regulation (EU) no.745/2017."

Made by a kitchen supply company, maybe looks a bit funny but is available in various colors and has 95% filtering capacity for one day. Apparently you can wash it in your dishwasher? Requires disposable round filters, but the simplicity of their shape and how they're installed makes me think some DIY filters for this might be possible down the line. I've ordered mine in Helsinki from:

Eiring - Kaikkea keittiöön - Eiring’s Kitchen
Nopea palvelu verkossa

Update: These arrived, and first impressions are that they are well made, comfortable, pretty easy to get a good seal all around the face, and it's really nice to not have something pressed right up against your nose and mouth. However, a teacher friend pointed out that the silicone muffles your voice when you talk. Also the filters are tricky to put in, and some of them arrived all crumpled (they'd been roughly stuffed in with the masks) so when I put them in there were gaps at the creases. Also I've found that if I breathe in and out very hard for a while, it's possible for the filter to shift a bit so I'm actually breathing through a small gap between the filter and the mask, which rather defeats the purpose.

However: I have a suspicion that a rubber gasket might help hold the filter in place and snug against the mask, and if that fixes it, this would be one of the best masks I've tried so far in terms of comfort. Or maybe Guzzini just needs to get themselves a better filter supplier. I've complained to them and they said "We will report your feedback to the quality department."

Rehe KeepSafe (98.7% hiukkasista)

Finnish company makes this, available in two sizes. Small size was too big for my kids.

"Oikein käytettynä Keep-hengityssuojain voi suojata käyttäjää ilman epäpuhtauksien, esimerkiksi hiukkasten, aerosolien, bakteerien ja virusten, aiheuttamilta vakavilta terveysvaikutuksilta. Käyttämämme materiaali suodattaa testien* mukaan 98.5 % hiukkasista. Keep-hengityssuojaimella on CE-merkintä. Tuotteidemme PolyBiotech -materiaali on testattu ja täyttää kirurgisten maskien tyyppi II -luokan vaatimukset (UNI EN 14683). Tuotteidemme suodatinmateriaali on biohajoavaa, nanoteknologiaa sisältävää 100 % kierrätysmateriaalista valmistettua käyttöä ja pesua hyvin kestävää polyesteriä, jota on kehitetty seitsemän vuotta. Kutsumme sitä PolyBiotech-nimellä. Materiaali on alunperin kehitetty muotiteollisuuden ekologiseksi ratkaisuksi, mutta totesimme sen olevan vihreytensä lisäksi erinomainen materiaali vaatimukset täyttävien hengityssuojainten valmistukseen."

I can't speak to the tests, because despite the asterisk there's no direct link to them. Still haven't found out what type II means, but UNI EN 14683 refers to, as far as I've found, (googles shakily) testing for how well it filters bacteria, and how easy it is to breathe through. Which doesn't necessarily address how it handles viruses. But it certainly does what it's supposed to do in terms of protecting others from you, and seems like it would filter at least some of what's around you for your own protection as well.

Trying it out:

First impressions on arrival: Super comfortable, feels a bit like a flannel sweater, easy to breathe through, the S/M size is a good fit and I can talk while wearing it. Wish the straps were adjustable, they're a bit loose on me. Don't love the straps in general; they seem a bit flimsy.

Running errands with it: It's a warm day today and I feel a bit like I'm wearing a facewarmer. Might be nice in winter though, outside, not sure about inside. Condensation forming from my breath, and though at first it holds its shape away from my nostrils, one side collapses a bit and I find myself breathing specifically through the now-moist fabric sticking to half my nose as I inhale, and this is harder than I would like. It's also getting a tiny bit itchy. When I take the mask off at home my face is all damp with small droplets and it's a relief to breathe again. Don't know yet if all masks simply are like this. Will find out as others arrive.

Senscommon ViralOff face mask (80% 3micron particle retention)

ViralOff on Senscommon site

"Anti-viral & highly breathable, >80% 3µm particle retention, COVID-19 Level 3 social mask, enhanced with ViralOff® technology* inhibiting 99% of viruses & bacteria, continuously active ISO18184:2019, >70 mm/s breathability ISO9237:1995, soft Oeko-tex® cotton comfort, well-fitted design with nose clip, lab-tested and made in Portugal. *ViralOff® Polygiene technology is an antiviral treatment that continuously protects the treated article from viral contamination, reducing 99% of bacterial activity and viruses like Influenza A, Corona, Hepatitis in 2 hours. The active ingredient is a biocide and it is made of a reaction mass of titanium dioxide and silver chloride and the product is not nano-silver. In practise it means you wear the mask for an event/shopping/travel, take it off and after 2 hours you know for certain it is clean and safe to put it back on for the next trip. For best performance and sustainability, wash less and only when needed (40ºC). ViralOff® efficiency slightly reduces after 15 washes."

I'm not sure what "COVID-19 Level 3 social mask" means, but if I'm reading this right it filters 80% of particles and would therefore be something like FFP1? Anyway, either this is cleverly obfuscated marketing, or this seems to offer a bit more protection than your standard cloth mask. It would, again, be very convenient if it essentially cleans itself after two hours; both copper and silver do have antimicrobial properties (Note: do not eat silver you fools unless you want to turn bluish gray), but how copper affects Coronavirus is still up for debate.

Impressions: Nose wire! Yes! However, I was surprised to see that they are one cloth layer thick, which certainly makes them easy to breathe through but does not fill me with confidence as to their function. Better than nothing though. Until someone verifies their claims I would think of these as protecting others more than myself. Also the ear loops are not adjustable so I either have to use the small size which is a tiny bit too small for my face(fits the overall topography though), or make the medium straps shorter. In general these sizes seem to run large.

These smell strongly of chemicals on arrival so I'm going to wash them before using them, even though it says it loses efficiency after 15 washes. Also 40ºC seems an awfully low temperature to wash these in.

U-Mask Model Two (FFP3, 99%)

U-Mask Official Store | The Only Biotech Mask In The World
U-Mask is the first biotech mask super effective against viruses, bacteria and air pollution. Explore the new U-Mask Model 2, featuring a lycra cover and replaceable refill with our bio layer that lasts 200 hours. It is comparable to an FFP2 & FFP3 standard of protection and performs better than a t…
"U-Mask is the first biotech protection mask that provides a protection standard comparable to an FFP3 and lasts up to 200 hours of effective use. For example, if used for 8 hours a day, U-Mask will last about 25 days. The refill features four layers of filtration, it is self-sanitizing and anti-proliferative, meaning that it prevents the growth and spread of viruses and bacteria on the mask surface. The cover is made of an Econyl® Lycra, which features a nylon thread recycled from the oceans' plastic. The result is an extremely comfortable fit for prolonged periods.
The package contains: 1 cover in Econyl® Lycra obtained from the oceans' plastic and 1 refill with four filtration layers, with our exclusive bio-active layer developed by U-Earth. The cover can be washed in the washing machine at 30 °C while the refill can be cleaned with a damp cloth or a sanitized tissue."

Only available in one size, but seems pretty hardcore at FFP3, which is like an N99 vs an N95. The outside is basically swimsuit material, and the filter element seems like an N95 cut to size with some black color added. I am skeptical about just wiping the filter clean and using it continuously, but what do I know. Has no nosewire and for me this meant gaps at the top of it. Mask is 39€ and shipping to Finland is 35€, so if these are any good, getting friends together for a group order is probably a good idea.

I've tried these, and have not been happy.

PureWaste kangasmaski

Kangasmaski - meleerattu harmaa
Tuotekuvaus:Pure Waste kangasmaski on valmistettu 100% kierr&auml;tetyst&auml; puuvilla-polyesterista. Maskimme on pest&auml;v&auml; ja uudelleenk&auml;ytett&auml;v&auml;. Huomaathan, ett&auml; maski ei ole standardien mukainen, joten se ei t&auml;yt&auml; terveydenhuollon tiukimpia kriteereit&auml;…

I love their t-shirts and have lots of them, highly recommended! But this is clearly not the ideal material for a mask. Gets damp really easily and once it's damp it clings to your nose and mouth on inhale and essentially blocks your breathing. So I won't be getting more of these.

Got more I should try? Send me a message.

Other masks and DIY:

Melt-blown nonwoven polypropylene keeps coming up in the articles and posts I've been reading as a very effective filter. You can get this from Amazon but I would rather buy direct from a Finnish company. Let me know of a source if you know.

Friends have bought and liked these masks:

Facebook post collecting Finnish companies making masks:

Yrittäjien ja taiteilijoiden koronatuki
Koronavirus on uhka terveydelle, mutta sen varotoimista johtuvat taloudelliset vauriot aiheuttavat myös paljon inhimillistä kärsimystä. Työpaikkoja suljetaan, tapahtumia ja yhteistilaisuuksia...


Mask and filter material observations:

A very well-informed friend of mine said the following about masks they've been making:

  • If you can't smell your cooking that's a good sign. Also some smoke particles can be similar sizes to respiratory droplets and even viral particles, so if you can't smell someone's cigarettes or pot, that's a good sign. Note: cloth masks will let you smell everything, but they still help.
  • The general standard of filtration is a layer of non-woven polypropylene in the filter, with an electrostatic charge (that's going to catch more droplets and virus than anything else). It's also watertight.
  • Inner layer of thin cotton, mostly for comfort and moisture barrier
  • Outer layer of quilter's cotton, thicker and a little stiff, which is better for comfort because it holds the mask away from your face and is still breathable.
  • Nose wire made of coffee bag tie will last a lot longer and not fatigue as much as the materials used in the disposable masks
  • How you attach it to your face is super important; even a mask with a good fit isn't going to stay that way if it's bothering you or falling off. This is entirely personal preference though (ear loops vs ties, etc)
  • Clean via warm soapy hand wash and hang dry; preserves the filter layer and form longer. (Here is another friend's take on washing masks, and a VTT professor's take, and THL's advice. )

Mask filter materials comparison:

20 DIY Face Mask FILTER Materials Tested & Compared (Study: April 2020)

DIY mask designs:

PDF: Jesse mask pattern and guide

Martat maskmaking guide:

Kasvomaskin ompelu- ja käyttöohje