NOTE: I am not a doctor, but I have two sisters and a father and a best friend who are, and I’ve spent much of the last week researching these questions in depth.


Somewhat. The recommendations re: their use have shifted in the last week; the CDC has recently relaxed its guidelines on masks, and has even said that a bandana is better than nothing. We are currently so short of masks that many healthcare workers are going without masks at all, or reusing a single medical mask, the kind that was intended to be disposable. (One doctor I spoke to compared that practice to re-using a snotty face tissue — something you only do if you’re desperate.)

We are currently facing a severe shortage of PPE (personal protective equipment, such as masks) for first responders and healthcare personnel, and many hospitals are requesting that the community help make masks to cover the shortfall. Homemade cotton masks are generally washable as well, which helps extend their utility.

Here is an account from a healthcare worker’s family about how they’re jerry-rigging PPE for him:

This is my brother. We were getting him ready for his shift today at the ICU, which has been transferred into a Covid…

Posted by Noha Moustafa on Saturday, March 21, 2020

It is obviously better to have this equipment mass produced properly, and we have to assume that factories around the world have shifted to this work, but it takes time to retool factories and time to train workers, so right now, we have a gap where homemade masks can be very helpful.


Masks sewn with a layer of filter fabric are about 50% as effective as medical masks. Doctors with access to medical masks may still choose to save those for use while treating sick patients, and use the home-sewn mask for well visits with babies who need vaccination, for example.

This is a good article that is written clearly and explains why you might choose a cotton t-shirt for filter fabric over a doubled over dishtowel, with links to substantial studies:

This is the most common tutorial on how to sew such a filter mask:

Some hospitals are also asking people to sew mask covers, to go over N95 masks and extend their efficacy. I haven’t seen research on that yet.


You would ideally know how to use a sewing machine, and have access to one, as it would be very slow to do these by hand. You can learn how to use a sewing machine in 2-8 hours, depending on how quick you are at picking up that kind of thing, from YouTube tutorials. But beginners will likely have trouble with the machine, get frustrated, etc. So if you have a machine you don’t know how to use well, you may do better loaning it out to someone with the skills. (You can certainly hand-sew one or two in a few hours, though.)

There are multiple styles of masks, of greater and lesser utility for different purposes. Do you want to churn out a lot quickly? Do you want to make a mask for a loved one that will be comfortable and well-fitting? You may want different masks.

See this comparison of three different styles:

MASK PROTOTYPING RESULTS: I decided to make three of the fabric face masks that have been popularly circulating, and it…

Posted by Stephanie Syjuco on Saturday, March 21, 2020


There are various materials needed — cotton fabric, non-woven filter fabric, pipe cleaners (the kind kids play with), elastic, thread. You may have some of these on hand, and can donate them; you can also buy supplies for someone who is sewing, and drop them off to them.

Here in Oak Park, mask efforts are being coordinated on the Facebook group, OP Mask Group:



(These filter 95% of coronavirus particles.)

Yes, potentially, if you have access to a 3D printer and the right kind of PLA material to print with. There is an open-source pattern going around, and right now, I’m waiting to hear from some doctors who have been 3D printing a mask, and will be fitting it and then having it tested for efficacy by a pulmonologist. Once they report back, if it seems like it works, I’ll post with more details.

But the basic link on it is here:

Note that 3D printing is a very slow process, so if this works, we may be asking everyone with access to a 3D printer to help produce masks. The good thing is that these are washable, so can be be sterilized and reused over and over.


There is also a new type of mask developed by an Israeli scientist that looks promising; it’s not available yet, but if you’re in the medical / tech / production arena, you may want to look here for details:



This is a complicated answer.

• If you are expecting high exposure to the virus (healthcare workers, maybe grocery store clerks, public transit drivers, etc.), then yes.
• If you are already sick, then yes.
• If you are immunocompromised, elderly, or otherwise at high risk — probably yes, with training.
• If you are healthy, and not in contact with those at high risk, then your wearing a mask is not a priority while we have a shortage, but may be fine once the shortage has been addressed.

(And please, if you have extra masks lying around that you don’t need, consider donating them. Call your local hospital, let them know that you’re swinging by and will drop them off outside emergency. Check your garages and wood shops; N95 masks are often used for filtering particles in those situations. Even if you don’t use them, a previous homeowner may have left some.)

Aside from shortages, the main reason to hesitate before recommending that everyone wears masks is that research shows (and I’m sorry I don’t have the study at hand right now, but I’ll try to go dig it up soon) that for the average person, wearing a mask puts them and the community more at risk for catching the disease. Why? Three reasons:

  • the masks aren’t that comfortable, and when people first start wearing them, they tend to touch their face far more often than normal, adjusting and readjusting the masks, thereby potentially transferring particulates of virus directly to their face. Not good.
  • when you breathe on the mask, the moisture in your breath collects there, and over time, the viral load on the fabric itself builds up, so that if you are sick (and remember, you can be contagious for several days before you become symptomatic), you’re concentrating virus in one place, making it more likely that you’ll accidentally transmit it while touching a doorknob, an elevator button, etc. In the field, healthcare professionals are trained to change masks very often; everyday people don’t know how long is safe to wear one
  • the masks give people a false sense of security, and as a result, many people begin to relax other precautionary measures — going out to interact with others more often, not maintaining at least six feet of distance, etc.

So if you choose to wear a mask, please be very aware of the above, and consciously seek out training in how to wear one effectively. (I’m going to try to research whether there are YouTube tutorials in this. More soon, hopefully.) For myself and my own family, we’re not wearing masks currently. (And of course, we’re mostly staying at home.)

3/22/19: That’s what I have for now. I based this on research + many conversations with doctors, and I’ve had one infectious disease doctor check this over and vet it. I will continue to revise this on the OP Coronavirus Citizen Response group as seems wise, and also here, noting any updates with a date.