DIY Cloth Mask 101: Everything I Learnt

DIY Cloth Mask everything I learnt about sewing face masks for COVID

*Wearing the unmodified 3D mask (left) and the modified moulded cup mask (right)*

Well, look at the time. It’s already August and we are still in the middle of a pandemic. Mask-wearing is currently mandated in Singapore and many other countries, and this new norm does not seem to be changing any time soon. Just like many other home-sewers, I have turned to making my own DIY cloth mask to wear in public.

By wearing a mask in public, you can reduce your risk of inhaling harmful pathogens in the environment. Additionally, you can also protect others by limiting the spread of large droplets that are expelled when you talk, cough, and sneeze in public. This is especially important when current evidence suggests that persons infected without the virus can also transmit the virus while remaining symptom-free [1].

There are so many DIY cloth mask patterns that are available for free on the internet now, it's hard to pick the "right" one. Fortunately for me, I have only tried 2 and found the perfect one for myself.

PATTERNS

The Moulded Cup

Wearing unmodified adult size moulded cup mask using pattern by Make My Lemonade

One of the mask patterns I tried is the moulded cup design by Make My Lemonade. This is also similar to the one offered by Craft Passion and Mimi G Style. If you don't have access to a printer, you can check out the measurement pattern that is available on Mimi G's site.

There's no specific reason for why I ended up with the pattern by Make My Lemonade. I don't even speak French! It just happened to the the first pattern I came across and so that's what I ended up with. Personally, I found depth of this moulded pattern too deep for my face. I ended up modifying the pattern to make the curve less concave for a better fit on my face. I also lengthened the sides so the mask covers a bigger area on my face.

*Image only serves to illustrate modification and is not to scale*

*Blue = modified as per illustration above*
*Red = original adult size using pattern by Make My Lemonade*

Other than the fit issues, I also found the angle of the sides to sit too low on the face. Because of this, the elastic has the tendency to rub the top of my ears. Wearing this mask for a prolonged period makes my ears sore.

Since returning to work, I have also found that this mask slips down my nose as I talk. It doesn't look like it, but my husband also reported that the mask wears loose on his nose (see photo below). Many people that I have talked to on Instagram have also mentioned the same problem. Perhaps adding a nose wire or modifying the ties to go around the back of the head might mitigate these issues, but I was ready find another pattern. (And my husband does not want the fiddly around-the-head ties)

The 3D / Boat

*Wearing unmodified 3D mask. Upper left photo shows how I tuck the lower flap in to avoid having the occasional "turkey neck".*

1. Cut rectangles (black numbers)

2. Cut shape (red numbers)

Illustration based on tutorial by Romilda Dias

(Link to video tutorial below)

The second pattern I tried is the 3D mask design by Romilda Dias which I found via Youtube. The video is in Portuguese but you don't really need to know the language to understand the steps. It is a self-drafted mask pattern with simple, straight seams that are great for beginner sewists. Again, this is great for someone like me who has no access to a printer when I was in lockdown. The simple shape of the pattern also reduces fabric wastage, an issue I had with the moulded cup design.

While I made numerous modifications to the moulded cup mask, I made none to this design. I had a lot of requests for the link to the video tutorial via Instagram; everyone I have recommended this pattern to have also fallen in love with the simplicity of this pattern, just like me.

The potential issue with this pattern is the "one-size-fits-most" design. While everyone I recommended this pattern to had no complaints about the sizing, I decided make a bigger version for my husband. My husband usually has issues with finding RTW shirts to fit his neck. Also, the size of his little finger is the size of my thumb, so I thought making a bigger mask was the right thing to do! Perhaps size modification was explained in Portuguese in the same video or available in other videos by Romilda, but I decided to try sizing the pattern up on my own.

To do this, I asked my husband for the measurement of:

width of his face (from ear to ear)
height of his lower face (from the middle of the nose to the end of the chin).

*"Umm... maybe you only needed to make it bigger by 20%."*

Highlighted numbers are modifications I made based on the width and height of my husband's face. This is only for reference. Again, this is too big!

Floral = original

Blue = enlarged .. and too big :(

I used those measurements to cut out a rectangle, then took off 2.5cm from each end to make the tapered design just like the original tutorial. Unfortunately, the mask ended up being a wee bit too big for him (see photo above). I said "wee" just to save myself some face. It's functional, of course. But is it the best size, definitely not.

My husband suspects that the original size might have fit him just fine. For anyone who is thinking about sizing up, I recommend simply increasing the length and the breadth of the original rectangle by only just 0.5 - 1 cm (e.g., 12 cm x 23 cm).

(Note: He's in the US at the moment while I am still in Singapore, so making masks for him remotely was extremely challenging!)

The other patterns

After all this mask-sewing, I don't think I need to sew any DIY cloth mask for myself for a while. But if I need to make more cloth masks again, the designs by Dhurata Davies and Japanese Sewing Books are next on my "to-try" list. Of note, the 3D mask design by Japanese Sewing Books is partly inspired by the mask by Romilda.

Both mask designs offer a range of sizes. However, they are printable patterns, so access to a printer is crucial for making them.

MATERIALS

Most authors for these mask patterns have provided fabric suggestions along with the free patterns. After sewing a number of masks, I also a personal preference towards certain fabric types when making DIY cloth masks. Since new studies are constantly offering new information on the filtration abilities of homemade masks, I thought it would be interesting to provide a summary of what we know so far.

Number of layers

How many layers of fabric is needed for good protection? To put it simply, the more, the merrier [2].

A recent study by Bahl et al. (2020) demonstrated that a double-layer cloth covering is significantly more effective at minimising the spread of droplets during sneezing and coughing. Following this idea, the authors suggested that a 3-layer cloth mask should be recommended for homemade masks. If you are not squeamish, check out the striking visualisation of droplet spray during coughing and sneezing from the study! [2]

Types of fabric

Experts seem to agree that heavyweight quilter’s cotton with a high thread count / tight weave provides the best protection [3][4]. More specifically, a cotton with 600 threads per inch (TPI) outperformed a cotton with 80 TPI to a large extent [3].

In practice, I think it is hard for home-sewers to know the specific thread count of a fabric. My suggestion is to hold the fabric against the light for a visual assessment of the tightness of the weave. Doing this by wrapping the fabric over a cardboard tube makes the visual check easier. Naturally, the tigher the weave, the greater the opacity of the fabric when held against the light.

Visual assessment using a cardboard tube with the fabric wrapped around 1 end. The tube is held against a light source.

This photo is unedited and shows 1 layer of medium-weight quilting cotton.

*Visual assessment of a dress-weight polycotton. These photos are unedited.*
*Left = 1 layer; Right = 2 layers*

To ensure better protection, you can pair the tight-weave cotton with another material. Synthetic materials retain electrostatic charge that can filter aerosols (i.e. very small, airbone particles that can travel and serve as a possible transmission of viruses). Because of that, using synthetic materials for making cloth masks improves the filtration ability of DIY cloth masks. Some hybrid pairs that you can use to make 2 or more layers of your cloth masks are: cotton+flannel, cotton+silk, and cotton+chiffon. [3]

If you are concerned about the breathability and comfort dense woven fabrics, T-shirt fabrics may serve as an alternative. T-shirt fabrics (i.e. knits) used in 2 - 3 layers can be effective in blocking the transmission of droplets from the wearer [5]. However, as this study is a pre-print and has yet to undergo peer-review, this information should be used with caution.

Filter or no filter

Many of the DIY cloth mask patterns offer a optional pocket for inserting a filter. Several studies have also investigated the use of filters in conjunction with homemade cloth masks. Turns out, many materials that are easily found at home are suitable and effective in serving as a filter for homemade masks!

For example, 4 layers of kitchen towel with 1 layer of polyester cloth is found to be highly effective in blocking out transmission of virus via aerosols from the environment to the wearer [6].

Spunbound polypropylene, which is the material used in many reusable grocery bags, disposable workwear, and interfacing material for sewing (not the woven type), can serve as a highly effective filter [7]. Dried hypoallergenic wet wipes and baby wipes are also materials recommended for use as a filter for homemade masks [8].

Interestingly, it has also been suggested that wearing an additional layer of nylon stocking over your existing DIY or surgical masks can also improve their filtration efficiency to some degree [9]. However, this recent study has not undergone peer-review. So, you can hold off cutting your stockings and consider using other common household materials that have been studied instead!

LAST WORDS

At the end of the day, a DIY cloth mask is not a hospital-grade surgical mask or N95 respirator. However, by following some of these recommendations when making and wearing our homemade masks, we can reduce the risk of spreading and catching the virus to a large extent:

Picking a pattern that gives a good fit on the face [3][7]
Using 2 - 3 layers of fabric [2]
Adding a spun bound polypropylene filter [7][8]
Maintaining physical distancing [10]
Practising good hand hygiene [10]

Now, this blog post turned out to be much longer than I anticipated. I hope the information is helpful for you when considering making and/or buying a reusable cloth mask. If you have a favourite mask pattern that I didn't mention in this post, please share it in the comments! I am also happy to try to answer any questions about mask-sewing and mask-wearing in general.

Stay well and be safe! x

Disclaimer: I am not a medical professional and I do not have a background in microbiology. The research presented in this post is a literature summary rather than a literature review. This means I did not review the methodology and interpretation of results provided in the studies. Please do not hesitate to contact me if you feel that I have misrepresented the information in any way.

References:

[1] Furukawa, N. W., Brooks, J. T., & Sobel, J. (2020). Evidence Supporting Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 While Presymptomatic or Asymptomatic. Emerging Infectious Diseases, 26(7). https://doi.org/10.3201/eid2607.201595

[2] Bahl, P., Bhattacharjee, S., de Silva, C., Chughtai, A. A., Doolan, C., & MacIntyre, C. R. (2020). Face coverings and mask to minimise droplet dispersion and aerosolisation: a video case study. Thorax, 0, 1–2. https://doi.org/doi:10.1136/ thoraxjnl-2020-215748

[3] 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, 14(5). https://doi.org/10.1021/acsnano.0c03252

[4] Verma, S., Dhanak, M., & Frankenfield, J. (2020). Visualizing the effectiveness of face masks in obstructing respiratory jets. Physics of Fluids, 32(6), 061708. https://doi.org/10.1063/5.0016018

[5] Aydin, O., Emon, M. A. B., & Saif, M. T. A. (2020). Performance of fabrics for home-made masks against spread of respiratory infection through droplets: a quantitative mechanistic study. https://doi.org/10.1101/2020.04.19.20071779

[6] Ma, Q.-X., Shan, H., Zhang, H.-L., Li, G.-M., Yang, R.-M., & Chen, J.-M. (2020). Potential utilities of mask-wearing and instant hand hygiene for fighting SARS-CoV-2. Journal of Medical Virology. https://doi.org/10.1002/jmv.25805‌

[7] Zhao, M., Liao, L., Xiao, W., Yu, X., Wang, H., Wang, Q., Lin, Y. L., Kilinc-Balci, F. S., Price, A., Chu, L., Chu, M. C., Chu, S., & Cui, Y. (2020). Household Materials Selection for Homemade Cloth Face Coverings and Their Filtration Efficiency Enhancement with Triboelectric Charging. Nano Letters, 20(7). https://doi.org/10.1021/acs.nanolett.0c02211

[8] The Science Behind A DIY Reusable Mask Using Household Materials. (2020). https://www.a-star.edu.sg/docs/librariesprovider1/default-document-library/news-events/news---content-block/astar-diy-mask-science_website_apr-2020.pdf

[9] Mueller, A. V., Eden, M. J., Oakes, J. J., Bellini, C., & Fernandez, L. A. (2020). Quantitative Method for Comparative Assessment of Particle Filtration Efficiency of Fabric Masks as Alternatives to Standard Surgical Masks for PPE. https://doi.org/10.1101/2020.04.17.20069567

[10] Chu, D. K., Akl, E. A., Duda, S., Solo, K., Yaacoub, S., Schünemann, H. J., Chu, D. K., Akl, E. A., El-harakeh, A., Bognanni, A., Lotfi, T., Loeb, M., Hajizadeh, A., Bak, A., Izcovich, A., Cuello-Garcia, C. A., Chen, C., Harris, D. J., Borowiack, E., … Schünemann, H. J. (2020). Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis. The Lancet, 0(0). https://doi.org/10.1016/S0140-6736(20)31142-9