The most effective mask against COVID-19 is called an N-95 respirator. DIY masks & PPE (personal protective equipment) are not N-95 respirators. Most DIY masks are less effective due to their materials and lack of regulatory approval. It is important to understand proper care and use to prevent further risk of infection. The current recommendations for protecting yourself and others is physical distancing.  Masks can prevent you from spreading COVID-19, but do not protect your eyes. 

Please read this entire guide prior to making your mask!

The Team

Tutorial & Pattern
Alysia Myette
L Wilkins + Maggie Huang
Tutorial Graphics
Dushan Milic

Last Update April 8, 2020

This guide will be updated as information evolves with the rapidly changing COVID-19 crisis. Although our team is dedicated to updating this regularly, please note that information can become out of date.

Should you wear a mask?

The recommended and most effective strategy is physical distancing (staying a minimum of 6 feet away from others). Dr. Theresa Tam,  the top doctor at the Public Health Agency of Canada, has stated that wearing a mask may protect you from spreading the virus (pre-symptomatic and asymptomatic) but that wearing a non-medical mask may not protect the wearer from others.

There is conflicting research on the effectiveness of masks for the general public due to supply concerns and the potential for improper use (which puts the user at risk of infection).

Generally, masks are only effective if worn properly. If not worn properly, masks are ineffective and can be harmful. If you believe your mask is more effective than it is, it can also provide a false sense of security. Children are often unable to fully comply with mask procedure, which can make their masks ineffective.

If you do choose to wear a mask, we want to help you make the best one that you can. We’ve tried to create a DIY design that is as safe as possible.


It is critical that you take good care of your mask and follow correct procedures for use and sanitation. Improper use and care will result in additional risks to yourself and those around you.

Some masks are disposable and some are re-usable. Make sure to correctly understand the material you are using.

The shape and fit of your mask is very important.

The mask should fully cover your nose and go under your chin. Improper fit is often cited as the reason for ineffective mask use. There should be a pinch mechanism at the top of your nose to hold it in place. The masks should be domed outward (either with pleats or other methods) and not rest against your mouth.

Ensure you wear your mask properly

  • Properly wash hands for at least 20 seconds before putting on your mask.
  • Make sure your mask fits you: It should cover your nose and mouth and be domed outward.
  • Make sure the mask is firmly pinched around the top of your nose. Proper adjustment of the nose piece can also prevent fogging up of glasses.
  • Do not touch your face or adjust your mask after putting it on.
  • It is critical to wash your hands before and after adjusting your mask to limit potential exposure.

Remove and dispose of your mask properly

  • Wash your hands properly before removing your mask.
  • If you are using a disposable filter inside your mask, discard it after every use.
  • If your filter is washable, clean it properly.
  • Store clean and used masks in separate airtight containers in different locations.
  • Remove your mask from the ear/head ties, and do not touch the front of the mask.

Make sure your mask is comfortable

If your mask is uncomfortable, you will adjust it and risk contamination.

Make sure your mask is well fitted and comfortable to wear. Test your mask before wearing it outside (20 minutes is fine): breathability, mobility, speech (can people hear you?), warmth, and humidity. Adjust as necessary.

Only use a filter if you can comfortably breathe and are not limiting oxygen intake.

Cotton Masks

Remove and sterlize the nose piece prior to washing the mask.

Cotton masks can be washed in a machine. Use high temperature water and soap.

If boiling, do not do this for a long period of time. Light boiling is fine.

Sterilize Nose Piece

For non-porous nose pieces, spray down with alcohol/Lysol/Clorox or wash with antibacterial soap.

Felt & Non-woven Materials

Felt and non-woven filters are not suitable for reuse. Do not scrub with soap or put it in the washing machine. This reduces the effectiveness of the mask by stretching and misaligning the material.

Quarantine It

There is some evidence to suggest you can leave the mask in a dry, untouched place for at least 3 days.

Current research suggests that COVID-19 can live for 2-4 days on surfaces (depending on the material), so it is uncertain how safe this method is.

Alcohol Spray

You can use 60-95% alcohol spray to disinfect your mask but this does not 100% guarantee that all viruses are killed.

Spray the entire mask sleeve thoroughly.


Depending on the material of your mask, you may chose to microwave the mask for 2 minutes at 600 watts. Ensure you remove the metal nose piece and elastic before.

Using this method carries risk of fire. Please be cautious and do not leave the area unattended.


Do not use bleach on any type of mask. It can deteriorate the fibres resulting in an ineffective mask.

The Sun

Although there is some evidence to suggest the virus (much like MRSA & SARS) can be killed by exposure to UV-C light, we do not recommend leaving your mask in the sun. This has not been tested to be effective for COVID-19.


Please note that UV-LEDs (such as nail lamps) do not sterilize and should not be used to disinfect your mask.

Different fabrics alter the time a virus can survive

Porous materials potentially catch, dry and break apart virus particles.

Smooth surfaces like vinyl and leather can be wiped clean.

Spandex and polyester may retain particles longer than breathable cotton.

Metal, plastic buttons, zippers and other hardware may hold viruses longer (up to 2-3 days based on our current research).

How do face masks filter particles?

Masks work by catching particles in the fibres when you inhale, and catching droplet particles you breathing out.

It is important to understand that many respirators you might already own are built for air filtration and are not the same as medical masks. Masks that have valves do not filter your exhale. Some commercial dust masks may say they can be re-used extensively, however their imagined use case is different and contamination is not a factor.

Single-use face masks and surgical masks typically capture large particles that are 0.3 microns in size. These include vapour, droplets and water particles. Respirators like the N-95 can filter smaller particles of 0.1-micron (the size of the Corona virus).

COVID-19 virions are spherical with diameters of approximately 125nm and are commonly transmitted through droplets.

The further your distance, the more reduced your exposure to potentially dangerous particles. At 6 ft distance, the amount of ambient particles smaller than 4 microns is very low.


Material choice is critical to the construction of any PPE. Masks filter by trapping particles, but should also be breathable. If your mask is not breathable, it will not function as a filter. Choose the best material you have available while keeping in mind how your material choices affect your mask.

Select a tighter woven cotton for the exterior of your mask if possible. We advise using 2-layers of 100% tightly woven quilting cotton for the exterior of the mask and waffle weave "tea towel" cotton for the filter. Both are washable.

Choosing the right filter

Our mask design has an optional middle pocket for an additional layer of filter which can dramatically increase effectiveness. This may be beneficial if your mask is made of a lighter material. Please be mindful of your comfort (breathing, speech, humidity, etc).

Quality of the fabric, thread count and tightness of the weave/knit can heavily impact the viability of the filter. Nonwoven materials make for effective filters but are not washable in this context and therefore not reusable. A common example of a nonwoven material is craft felt.

Be mindful of your breath making the mask wet which will increase the risk of bacterial growth. If your filter is wet after use, discard it if it is not a washable material.

The following materials make effective filters. Note that materials vary based on brand and quality.

  • Vacuum Cleaner Bag
  • Waffle weave cotton dish cloth/”tea towel”
  • 100% cotton shirt / quilting cotton
  • “Non-Woven” Material – cloth found in rags, diapers, gauze, tampons. (not suitable for multi-use)
  • CSR Wrap (Reusable Surgical Wrap)
  • Reusable fabric shopping bags with cross-hatch weave
  • Polypropylene
  • Microfibre, woven polyester made of textured yarn (does not have a shiny, stiff appearance and looks / feels like real cotton)


Waffle Weave Cotton

You can find this material as a dish towel/tea towel easily. It quickly dries out after use and can be fully machine washed in hot, soapy water. It is ~80% effective (efficacy varies depending on material composition). Ensure you use a new, un-used towel for your filter.

Single Use

Felt & Non-Woven Materials

Felt is a common nonwoven material. Nonwoven materials make for effective filters but are not washable in this context. We would not recommend reusing nonwoven filters.

Single Use

Furnace Filters

Furnace filters are effective at letting air through while trapping particles. HEPA filters, rated as MERV 17-20 removes at least 99.97% of airborne particles. MERV 11 furnace filters rating between 13 - 16 capture particles 0.1 microns (the size of COVID-19). Lower grade filters are also somewhat effective (Merv-11 is most commonly found). These are disposable after each use (not reusable).

Single Use

Nonwoven Polypropylene

This material can be found in your home, often as a water-proof, reusable shopping bag. You cannot wash this material without damaging the fibers and it cannot be heated without melting. Dispose of after use.

Salt Barriers

You can also use a salt barrier on your mask cover. This should only be done on cotton or woven material covers and filters. This process will damage the integrity of nonwoven materials.

Why are salt barriers great? 

Our research shows that salt may add an additional barrier to prevent viruses from penetrating the mask and may improve air filtration efficacy due to its moisture wicking properties.

Salt barriers are also beneficial if you are unable to use a filter due to comfort as they improve sterility of the mask.

To create a salt barrier...

Fill a pot with potable water (distilled or pre-boiled is ideal)

Bring to a light boil (about 190f) to improve salt solubility and overall saturation of the solution

Add salt until the point of saturation (undissolved salt will accumulate at the bottom of the pot after stirring)

Add drops of dish soap until the solution becomes very foamy

Add your woven cloth filters and stir

Soak for 10 minutes and then let dry thoroughly


100% Quilting Cotton (we suggest a light color to gauge dirt)
Waffle Weave Dishcloth / "Tea Towel"
20" Elastic or Cotton Ribbon Tape (1/8" - 1/4" wide)
2" Pipe Cleaner / Bendable Wire
Cotton Thread
Nose Piece (pipe cleaner, paper clip, craft wire, or similar)

Home Sewing Machine or Straight Stitch Machine (serger/overlocker is optional)
Pencil or Disappearing Ink Marker


We recommend your mask be made of 2 exterior layers of 100% quilting cotton. Although not ideal, you can also use a thick cotton shirt and/or add layers.

Layers do not double the effectiveness. They only somewhat increase effectiveness.

We have included an optional filter pocket in this design.

If you are hand-sewing, your stitching may not be tight enough to provide the same filtration as a machine-sewn mask. Consider using a 3-pleated dome method that does not have a center seam.

Step 1

Cut out all materials

We recommend that the exterior mask be 100% cotton while filter is 100% woven waffle weave cotton. Do not use synthetic materials as these are not CDC compliant.

Step 2

Curved Seam

Place both outer mask pieces of cotton with the exterior/visible sides together.

Sew the curved seam from top edge to bottom. Repeat for lining pieces.

Step 3

Iron seam allowance

Use an iron to press the curved seam allowance to one side on both the lining and outer-layer center seams.

Step 4

Topstitch seam allowance

With the seam allowance pressed to one side, topstitch down the seam allowance through all the layers about 1/8″ away from the seam.

step 5

Stitch the filter

Stitch the filter curved seam the same as you did with both the lining/pocket and outer layers of cotton.

Sew at a 1/4" seam allowance. Press the seam allowance to one side and topstitch the seam allowance through all layers 1/8" away from the seam.

step 6

Hem the pocket/lining

Hem the short edges of the pocket/lining piece of the mask. Finish each end of the mask with a 1/2" turn and turn hem.

step 7

Make a tube

Lay the sewn outer-layer piece of the mask right side up.

Lay the finished lining/pocket piece of the mask wrong side up on top of the outer mask, aligning the center seams. The outer mask will have a 1" seam allowance overhang.

Pin and sew along the top and bottom edges, creating a tube. Each seam will have a 1/2" seam allowance.

step 8

Flip it

Carefully clip into the 1/2" seam allowance as needed and turn the work right sides out.

step 9

Finish your hem

Finish the short edges of the outer layer of the mask with a 1/2" turn and turn hem.

Fold the hem towards the inside or pocket/lining side of the mask. Be careful when you stitch hem to not catch the hem of the pocket/lining as this is where the mask filter is inserted (optional).

step 10

Create nose piece pocket

Using a ruler, measure 1" from each side of the center seam in the mask and pin.

Topstitch 1/4" along the edge of the mask through all the layers, between pins, backstitching at beginning and end of stitched line.

step 11

Insert nose piece

Using tweezers, insert a 2" piece of piper cleaner or bendable wire into the nose piece pocket. Bend slightly at the seam into a small peak.

At this time, you may choose to insert a mask filter into the pocket of the mask, making sure to smooth any wrinkles.

step 12

Attach the elastic / ribbons

Start by cutting your elastic / ribbon into two 10" pieces.

These can be attached by threading each piece of elastic/ribbon through each hem of the outer layer of the mask using a safety pin.

These pieces can be adjusted in length to either fit around each ear of the wearer or to tie behind the head of the wearer.


Masks can be made for your community for personal use (not intended for medical use). If making for others, please use 100% cotton and a waffle weave tea towel as a filter.

Please ensure you are healthy and take precautions when making masks (wash your hands properly, wear a face mask, etc).

Package completed masks in a clean ziploc bag and include our guide on how to wear them which can be downloaded and printed.