One of the considerations when making cloth masks is what type of material to use. (See below about filtration percentages of fabric vs. medical grade masks.) Fabric masks should only be used when there are no medical grade masks available. If for personal use, the CDC is asking that people use fabric masks to leave more medical grade equipment available for medical and first responder workers.

Our preferred pattern asks for two layers of cotton or cotton blend. It’s best to use a lighter, plain color for the inside and a darker or more decorative fabric for the outside, so it’s easy to tell inside from outside.

Valley Masks is offering mask-making supplies, and will have them available at four locations in Northampton:
• South St. neighborhood: 52 Columbus Ave., home of Sydney (413-527-7880)
• Florence: 96 Oak St., home of Molly (413-336-1348)
• Ward 3: 96 North St., home of Joan (413-896-6943)
• Smith College neighborhood: 215 Crescent St., home of Stephanie (919-593-5984)
That means if you drive to these addresses, you’ll find two boxes on their front porches–one with complete kits to make 10 masks, and one box with bags of elastic for 10 masks. Take only what you know you can make in a short turn-around (eg. 2-3 days).

Sign up at DIY Masks of Western MA to make and deliver masks, and get supplies at one of the above four locations.

GetUsPPE – working to build a national, centralized platform to enable communities to get PPE to healthcare providers on the frontlines of the COVID-19 pandemic. Sign up as a maker space to see who is donating materials to PPE makers.

Please remember that no fabric mask is going to do 100% of the job of professionally made medical grade masks. But with massive shortages, some facilities are finding themselves with no supplies, so even a mask that does only 50% of the job of a medical grade mask is better than none or reusing already exposed disposables. These are stop-gap measures for the current desperate times.

Different materials will have different degrees of permeability for different size particles. Viruses like the novel corona virus COVID-19 (and its close cousin SARS) are a fraction of the size of bacteria, which are a fraction of the size of red blood cells, and so on. So choosing the most helpful fabric you can provides more help to healthcare workers.

This image is from one of the more descriptive reviews comparing materials and layering is from the folks at Smart Air.

» What Are The Best Materials for Making DIY Masks
Paddy Robertson, SmartAir, March 8, 2020

Talk to your local hospital about polypropylene fabric used for handling instruments and thrown out by hospitals daily. University of Florida’s department of anesthesiology has recently tested patterns for making masks of this fabric which has a high filtration rate for blocking particles.


The innovative mask uses Halyard H600 two-ply spun polypropylene that cannot be penetrated by water, bacteria or particles. It blocks 99.9% of particulates, making the masks about 4% more effective at blocking particulate material than the N95 masks, according to Bruce Spiess, M.D., a professor of anesthesiology in the UF College of Medicine, who made that calculation based on the manufacturer’s specifications.

The Halyard material, which comes in 4-by-4-foot sheets, is typically discarded after surgical instrument trays are unwrapped and before coming into contact with patients. About 10 masks can be made from one sheet …”

» Read the full article

Many hospitals throw out hundreds of these per day or more. NOTE: Ask your hospital if they can sterilize before donating to mask-maker groups. Depending on the facility you are contacting, they may refer to the department in charge of this material as Sterile Processing or Central Supply, and may call the product sterile wrap or “pinners”.