Kathryn Kaiser - Artist & Director

…or why did we choose 100% cotton & silk organza for our 3D Face Masks?

 

Our Process

After weeks of designing, revising and constructing many, many face masks for my family, I feel confident we have agreed on a style that suits everyone. We have a couple of children in our family on the autism spectrum, which meant comfort and wearability was paramount when I was working on face coverings for them. The final mask is breathable, comfortable to wear, fits very well on a variety of shapes and sizes, and is flexible enough to suit your needs and comfort level.

Our final decision on materials was 100% pre-washed premium quilting cotton (100+ threads per inch), with an optional silk organza liner. Silk (as well as other man-made fibres) is an electrostatic material that helps to increase the filtering capabilities (see ACS Publication link below). We found silk both cooler, and easier to breathe through than many of the synthetic fabrics we tried. We have constructed our face coverings with a casing to allow you to change out the tie. This allows for various comfort (and tolerance) levels, as well as the anatomical differences in all of us. We have optional electrostatic silk liners for extra protection, and optional nose wires for those who prefer.

 

Why Use 100% Cotton?

Recent studies show that well fitting, two-layer 100% cotton masks are between 69% and 79% effective in filtering organisms that are similar in size to flu viruses. Linen has 60-61% effectiveness. By comparison, an N95 respirator filters out at least 95% of particles as small as 0.3 microns, and a typical surgical mask has an efficiency of between 60% and 80%.

  • Because COVID-19 lives longer on plastics than on cotton fibres, fabrics with polyester, spandex and other man-made materials may retain viruses longer than cotton fabrics.
  • Cotton can be preshrunk to tighten the fibres, providing better filtering.
  • Cotton can be washed (and dried) in high heat with less damage to the fibres, unlike man-made fibres such as polyester and nylon.
  • Cotton is easier than many fabrics to breathe through. If breathing is uncomfortable, we won’t want to wear the mask. Some high filtering fabrics are virtually unwearable.
  • Good quality quilting cotton is the best cotton to use for face masks, as it is about 120 (and up to 200) threads per inch.

Some studies show that COVID-19 may only last about 1 day on (dry) 100% cotton, and about 3 days on polyester fibres. It will live longer on a mask or other face covering however. See links below.

Please note: COVID-19 will live longer on the inside and outside of a surgical mask. We are not certain at this point exactly how long it could remain active on cotton masks, but we must presume it could be as long as 7 days. “Strikingly, a detectable level of infectious virus could still be present on the outer layer of a surgical mask on day 7” — Study published in The Lancet (see below)

Also note that if your cotton mask is stored in plastic after wearing, it will remain damp. This will increase the time it takes for the virus to die off.  It is best to store masks in a pillow case, paper bag or net laundry bag.

 

New Word Health Organization Guidelines (June 5, 2020)

The new WHO guidance recommends that the general public wear cloth masks made from at least three layers of different fabrics “on public transport, in shops, or in other confined or crowded environments.” These are sometimes called ‘hybrid masks’. Hybrid masks have both mechanical and electrostatic filtration. WHO also suggests people over 60, or those with preexisting conditions should wear medical masks in areas where there’s community transmission of the coronavirus and physical distancing is impossible, and that all workers in clinical settings should wear medical masks in areas with widespread transmission.

 

Mechanical vs Electrostatic Filtration Explained

Mechanical filtration is simply the fabric physically catching the particles. Mechanical filters stop particles because of the small size of their pores. Generally with fabrics such as cotton, high thread count works best. The smaller the holes, the fewer particles can escape. Electrostatic-based filtration is a little different. Think of a static material such as polyester. These filters are electrostatically charged, and thus attract and capture charged particles. An electrostatic filter keeps the aerosols on either side of the static environment. See ACS Publication below.

 

Our Filter Material

N95 respirators are made from polypropylene fabric, which is also a good electrostatic filter material for cotton masks. Other fabrics in use as third layer filters are polyester and silk. All of these mentioned fabrics provide electrostatic-based filtration, in addition to the mechanical filtration provided by the cotton mask. Because both polyester and polypropylene can be difficult to breathe through, we have been using one layer of silk organza. The extra silk organza filter layer is optional, and is available as an upgrade in our face coverings.

 


Note that N95 respirators are still in short supply, and are needed for those working in the health care industry. However, if you are COVID-19 positive and must go out in public, or are caring for someone who is COVID-19 positive, a respirator or surgical mask is preferred.
Please continue to social distance. Even an effective and well fitting mask will not completely eliminate the spread of COVID 19, or any other virus.

 

For further reading

New York Times: What is the Best Material for a Mask? (has helpful info on filters as well)

Harvard Medical School: Preventing the Spread of Coronavirus

Forbes: How Long Does COVID-19 Last on Different Surfaces?

The Lancet: Stability of SARS-CoV-2 in Different Environmental Conditions

ACS Publications: Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks

Global News: WHO Recommends Wearing Masks in Public (& Guidlines)

 

See face covering use and care here:

See tips on prevention of fogging with eyewear here:

More product and purchasing info:

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