Why There Are “Holes” on My N95/KN95 Masks?

The holes, dots, or stripes you see on N95 or KN95 masks are how manufacturers stick the layered materials together. This is what helps keep your mask in shape. The varying patterns you see across masks shouldn’t affect the masks’ ability to filter out viruses or other particles.

Our data shows that these areas may have a lower filtration efficiency, however the N95 and KN95 standards test the filtration efficiency of the entire mask. The entire mask, together, must filter out 95% of the target particles in order to be certified an N95 or KN95 mask.

“Dots” or “stripes” visible when holding KN95 masks up to the light


3M 1870 that has “dots”

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17 thoughts on “Why There Are “Holes” on My N95/KN95 Masks?”

  1. The holes in my KN95 mask from China seem contrary for full protection. There are holes which I would think would lead entry for the COVID virus Delta. Should I toss them out?

    • I completely agree, the area looks to be compromised where the holes are………how couldn’t it be…..so that means that the virus could get in. Hardly seems like it would be protecting people

  2. ‘the various patterns shouldn’t affect the mask’s ability’ doesn’t very convincingly answer the question I think. ‘they shouldn’t’ negatively affect but do they or not? You say that is where manufacturers stick the various layers together. However, in these points the layer seems properly thin or even non-existed. They look like proper holes, and holding you finger behind it shows the colour of your skin. Maybe that is sufficient, but intuitively it seems contradictory the idea of having it all tightly closed.

  3. I agree I don’t understand that shouldn’t affect the mask is a good thing. It’s not a good thing. There should not be but appears to be holes in a mask. I returned an unopened box of a brand of masks because of these dots. When I asked the manufacturer about it, they said it’s where they are glued together. She said it doesn’t affect it but I wasn’t comfortable with that so I returned the rest that I had not opened. She said that they changed suppliers and that’s why the dots were there now. Again I’m not comfortable with that.

    Armbrust masks do not have those dots and so I am using them. They are USA made.

    • The Armbrust USA KN95 masks actually DO have these “dots”/”lines” (dashed lines…whatever you want to call them). I’ve bought KN95s from them and many other manufacturers (as well as N95s from many). Other “made in the USA” masks sold on Armbrust’s web site have these dots, too–you can clearly see them in the product images online if you haven’t bought the products.

      Even flat-fold NIOSH-approved N95 respirators have these “dots” where the mask layers are ultrasonically “welded” together to form the mask (look at 3M’s 9101 NIOSH N95 flat-fold respirator). Ear loops are similarly attached to masks using this “welding.” These dots/lines are places where the layers of material are sort of “melted” together to form and shape the mask so it will properly fit your face, and hold the layers together. Yes, you can see light/color through them, but you can also see light through the entire mask. But these are not HOLES.

      Most “surgical ” masks also have these dots/lines around their rims/edges/seams and where the ear loops attach. They just don’t have them on the main face covering part because they are pleated for fit, not “molded” to “3D” structure for fit.

      Cup-style N95 respirators don’t have these “welding” spots along the face covering part because they are manufactured differently–the rigid cup shape is formed differently. But you do often see these “welding” spots around the outer rim of cup-style N95s (just depends on the manufacturing process–how the layers are “glued” together and how the outer rim is formed). Duck bill N95s also generally wouldn’t have the welding spots on the main face part, but they generally do along the outer rim and edges/”seams.”

      Look at images of true NIOSH N95s, cup style, duck bill, and flat-fold, on manufacturer’s web sites (e.g., 3M’s) and you’ll see those same kind of dots. Certainly if you buy those N95s, you’ll see them and they compare to the dots in the KN95s.

  4. Try blowing air through a part of the mask that has no holes,then try blowing air through an area that does have holes. There is your answer. Air passes more freely through the area with holes. No matter what the manufacturer say’s, this is a defect.

  5. I’m so confused they say to use these masks now but when I opened one there are HOLES in it???? Like HOW can that block anything??

  6. Hi! Song here from Smart Air. In our tests, we found that the parts of the mask with ‘holes’ or ’stamped impressions’ did have lower filtration, but that overall, these masks were still able to filter out >95% of tiny virus-sized particles coming in.

    What’s important for these masks is the overall effectiveness at filtering out virus-sized particles, as that is what determines the mask’s ability to filter out COVID particles.

    Before using the mask, we recommend you check the mask is fully certified to the KN95 or N95 standard, and that the seller or manufacturer can provide you with a valid certificate to prove this. See this article: Step 2: ask the supplier for N95 or KN95 mask certificates (https://smartairfilters.com/en/blog/reliable-n95-mask-manufacturers-suppliers/).

  7. I KNOW these areas of holes are not good or normal. I order KN95 Masks over a year ago that I can hold up to light and NONE shows through! I now can’t find ANY that don’t. I have concluded that CHINA no longer cares of the quality they are sending to the US. Though these air holes are not discussed by the FDA or CDC they do say they no longer approve of the majority of KN95 masks being produced or available on such sites as Amazon. I purchased from WWDOLL, CHiSip and Boncare. All of these are listed on the “DO NOT BUY” list. They now advise to purchase only US N95 or
    Korean made masks.

  8. That link no longer works. Where can I find a list of approved manufacturers? I just ordered 100 KN95 masks from Walmart and those do have the holes in them in the main part of the mask and are made in China not Korea. I thought KN 95 meant they were made in Korea!

  9. So I experimented with inserting a pointed pin into the “holes” of my particular mask, which had about a hundred apparent perforations around the margins of this and that.

    They weren’t holes. Although it was a sharp pin, at least under light pressure, it didn’t pass through the “holes”. Instead, the mask deformed around the pin. So the “holes” were actually transparent, solid plastic-like material. As others have explained above, they were materials fused to create the mask’s structure.

    Which doesn’t mean some apparent “holes” aren’t real holes, etc., etc. Or that a bogus mask wouldn’t be given dangerously real perforations to make it look like the real thing. But there are ways to test, and yes some real N95’s appear to have perforations…they are actually utterly sealed.

  10. If you fill the mask with water. You will find water can not get through. So if water can not get through. It will be hard for particals to get through. Must be better than a cloth mask.

    • The clear areas aren’t glue, it’s where the layers of meltblown filtration material has been ultrasonically welded together. It makes the material translucent in that area, but doesn’t cause the mask to leak. I would be more concerned about leakage due to a poor face fit on a vertical fold flat mask.


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