Project Open Source:
Protective Face Mask

by Inside Weather

Not the fanciest thing you’ve ever seen, but it can work. And it’s already in your home.

Please share these resources freely with your neighbor & local businesses. While our team will gladly help produce these masks for anyone in need, our primary intention is to openly distribute design & manufacturing guidelines to everyday people & local businesses that have the basic tools at hand. These PDFs are for sharing. Please do your part to help & pass along!


The Problem

Our community is currently experiencing a shortage of protective masks which are in critical demand in both medical & civilian spaces alike. This week in an article by CNBC, the Department of Health and Human Services stated that “the U.S. has just 1% of the required respirator masks that would be needed for medical professionals” if the COVID-19 outbreak progresses. While new legislation, as described in an article by the Washington Post, is freeing up industrial mask manufacturers like 3M to increase their distribution, the updated output projection is “still well short of the 3.5 billion N95 respirator masks the U.S. could need in a serious pandemic.” With the lack of proper Personal Protective Equipment (PPE), the CDC has even recommended bandanas for healthcare providers as a last resort. So here we are. Despite efforts, supply chains will have challenges meeting demand & raw material shortages will persist.


There are only a handful of large players who can mass produce these so we shouldn’t rely solely on them for something we needed yesterday. YOU can make it. Everyone can have something that can still be effective.

Ben Parsa, CEO of Inside Weather

The Research

So what can we do without relying solely on the existing supply chains and traditional materials for construction? What are acceptable alternatives? We certainly cannot produce a “DIY” mask that is equally as safe and effective as say a surgical mask but we can do surprisingly well with some of the materials that we all likely have in our closets or still in the trunk from the last horder-status grocery run. Researchers at the University of Cambridge compared the effectiveness of household materials against a surgical mask. The results, as shown below, may not be as you’d expect. They indicate that an average household vacuum cleaner bag, for example, is 94.4% effective; that’s just 2% behind the effectiveness of a surgical mask which stands at 96.4%. A tea towel at 83.2% efficiency.

Household Materials’ Filtration Efficiency

Household Materials’ Filtration Efficiency

Source: Disaster Medicine and Public Health Preparedness

The Design Philosophy

The end goal of course is to enable our community at large to help keep each other & themselves safe by doing what they can, where they can, with the tools at hand. We need something that doesn’t require sewing, can be cut with household goods, allows whatever fiber readily available to be inserted and is ideally safely repurposable in some capacity.

Our Solution

It ain't designer but it'll do the trick. Reference the chart above to first see if you have the most effective fibers on hand and if not, go down the list. Many of your local small businesses likely have tools to produce these in bulk. For reference, this is the type of cutting machine we use but any laser cutter, clicker press, or other die cutting machines can work (think your local carpenter, stationary shop, or seamstress—they might be able to do a bit of bulk production which could go a long way).


The Ask

Make this at home for you & your neighbor if you need it. Even if you don’t, share it with your community in hopes it might pass by someone who just might.

From our house to yours, stay safe,

Do you need a batch made or know of someone who does?
Let’s (virtually) get in touch:

These resources are for informational purposes only and is not professional medical advice nor guarantee of outcome. Inside Weather is not responsible for errors or omissions in sharing these resources.