< Masks

How do you make your mask?

Text updated on 2020-06-10

You certainly have used clothes or other cloth textiles in the back of your closet, you have a needle and thread: we will guide you to make your first mask. Follow the pattern!

Homemade cloth masks are less effective than FFP respirators or surgical masks but they still prevent droplets from dispersing when coughing, sneezing, talking, or breathing. In addition, they can be washed and reused. In case of a mask shortage, they are the only ones available.

Step by step

Choosing the right fabric:
- Cotton 100% fine weft in 3 layers. For example T-shirt or jersey, tea towels, or a pillowcase. You should not see any light pass through if you look through then (too light) and it should not be easily damaged.
- A quilt has a filtering power too.
- Natural (not synthetic) silk in 4 layers.
- It is best to combine a layer of 100% fine weft cotton with a layer of flannel or two layers of silk or cloth.
Wash the fabric at high temperature to make it clean and shrink it as much as possible (important for cotton).
Vacuum cleaner or coffee filters are not intended to be used as breathing filters. Although they have a high filtration capacity, it is not known whether their use in a mask is harmful to your health (e.g., risk of moisture accumulation, allergies). It is therefore more prudent at this time to avoid them.
Consider inserting a disposable filter using two layers of pocket tissue or a layer of kitchen towel paper, into a washable cotton mask case. These could potentially provide considerable filtration capacity and are not likely to be harmful to your health.
You can add a piece of wire (e.g. stub wire from florists, twist ties, plastic-wrapped electric copper wires, metal fastener filing strips) as support for the nose.
Follow the instructions/tutorials below (there is guidance with or without seams)
Try on the mask. It must adhere well: no airflow at the top, bottom or sides. Be careful that the elastics or straps are not loose.
To improve the fitting of handcrafted or surgical masks, a piece of nylon pantyhose can be added on top. Improving the fitting of a mask can improve its filtration efficiency.
Having both the ear-loops and a pair of straps to tie around the back of the head to minimise leakage on the side can further improve the fitting.
Wash the mask (but not the filter if applicable) with water and detergent at 60°C before reuse. Iron at a high temperature.
But above all, don't let the sewing get in the way: if you can not make refined and stylish masks, construct simple seamless masks or use a scarf: some protection, even if ugly, is always better than no protection at all!

Instructions/Tutorials

Three types of masks: with stitching, seamless (but with cuts), and bandana-like (text in English, but instructions in pictures, 1 inch = 2.5 cm). https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html
French Specification AFNOR S76-001 2020 for home-made masks (in French, to be downloaded), an official guide to make masks, with links to tutorials

https://masques-barrieres.afnor.org/

Mask with elastics, stitching required (video in English). https://www.youtube.com/watch?v=4FB--BOyTiU
Mask with nose support, stitching required (video in English). https://www.youtube.com/watch?v=9K4dH3-LHLQ
Mask with a nose support, elastic ear-loops and straps, with 5 sizes including baby and children (HK masks)
- Step-by-step method (pattern, tutorials and user manual in multiple languages): https://diymask.site/
- Sewing machine method (video in Cantonese with English subtitle): https://www.youtube.com/watch?v=ZusqX4Cfa3w&t=46s
- Hand-sewing method (video in English):https://www.youtube.com/watch?v=KDYMMidIIBk&fbclid=IwAR0IuV-TWbMw5TDq705YzZFTHDQzfe5i1g7GpLHUjfnZ7vfIqCE9FLFQC6s

Sources

Prototype mask (seamless), tested during avian flu epidemic for its adherence to the face.

Dato, V. M., Hostler, D., & Hahn, M. E. (2006). Simple Respiratory Mask. Emerging Infectious Diseases, 12(6), 1033-1034.

Masks, even homemade ones, can prevent the transmission of the virus by acting as barriers that reduce the distance of droplet dispersal. This modeling study tested several types of fabric. Doubling the layers could further reduce the dispersal distance.

Rodriguez-Palacios, A., Cominelli, F., Basson, A., Pizarro, T., & Ilic, S. (2020). Textile Masks and Surface Covers - A 'Universal Droplet Reduction Model' Against Respiratory Pandemics. medRxiv.

Medical and handcrafted masks made of several types of fabric. Filtration efficiency, measured by viral particle counting, is compared between surgical mask (89%), vacuum bag (86%), cloth (72%), cotton fabrics (51-70%) and silk (54%). However, breathability was half as low with the filter aspirator as with the surgical mask or cotton fabrics.

Davies, A., Thompson, K. A., Giri, K., Kafatos, G., Walker, J., & Bennett, A. (2013). Testing the efficacy of homemade masks: would they protect in an influenza pandemic?. Disaster medicine and public health preparedness, 7(4), 413-418.

A layer of nylon (pantyhose) around the head above the craft or medical mask improves the fit to the face and greatly increases filtration efficiency by reducing air leakage. The filtration efficiency of commercial surgical masks increases from 53-75% (without nylon) to 86-90% with nylon; and from 28-85% to 581% for craft masks.

Mueller, A. V., & Fernandez, L. A. (2020). Assessment of Fabric Masks as Alternatives to Standard Surgical Masks in Terms of Particle Filtration Efficiency. medRxiv.

The mechanisms for blocking droplets and particles by masks are varied and change with the size of the particles. When there is no leakage, cotton fabric with a very fine weave and low porosity allows a high filtration of particles of size <300 nm (>80%) and >300 nm (>90%), comparable to the filtration of FPP2 (respectively, 85% and 99.9%) or a surgical mask (respectively, 76% and 99.6%). By combining very fine weft cotton with an electrostatic fabric, such as natural silk, microfibre, or flannel, a filtration efficiency comparable to a surgical mask is obtained whatever the particle size. The fit is crucial: a 0.635 cm2 hole on a 59 cm2 mask reduces filtration efficiency by up to 60%. Doubling the layers of the same fabric only marginally increases filtration.

Konda, A., Prakash, A., Moss, G. A., Schmoldt, M., Grant, G. D., & Guha, S. (2020). Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks. ACS Nano.

HK Mask homemade mask manual in English and traditional Chinese, with patterns and tutorials in multiple languages. The cotton mask sandwiching one to two sheets of pocket tissue or kitchen roll tissue achieved a bacterial filtration efficiency ranging from 45% to 91% (compared to the 98% of a surgical mask).

HK masks site. Last access on June 6, 2020.

A randomized trial showing that surgical masks are more efficient than home-made masks to protect healthcare workers of virus and influenza-like or respiratory illnesses.

MacIntyre CR, Seale H, Dung TC, Hien NT, Nga PT, Chughtai AA, et al (2015) A cluster randomised trial of clothmasks compared with medical masks in healthcare workers. BMJ open. 2015;5(4):e006577.