Summary of the best materials that you are likely to find:
- For the mask itself, use tightly woven fabric that will withstand the heat of sterilization, like 100% cotton twill or denim. Canvas or duck fabric may be good too. The rule of thumb is: ““Hold it up to a bright light,” said Dr. Scott Segal, chairman of anesthesiology at Wake Forest Baptist Health who recently studied homemade masks. “If light passes really easily through the fibers and you can almost see the fibers, it’s not a good fabric. If it’s a denser weave of thicker material and light doesn’t pass through it as much, that’s the material you want to use.”” Prewash fabric in hot water to preshrink it. Do not use scented detergent, fabric softener, or dryer sheets. Material must come from a nonsmoking home.
- For the ties, 1/4″ elastic or ties made out of cotton bias tape, cotton ribbon, or 1.5″ strips of knit fabric cut across the grain are good
- For nosepieces, try double wire clips from the tops of coffee bags and bread bags, doubled pipe cleaners with the ends bent over to protect the nose, and pieces of aluminum pie tins cut 1″ x 3″, trifolded lengthwise and the ends folded up about 1/8″.
Almost any breathable design that fits over a respirator and can be worn securely can be used to protect an N95 respirator from soiling, in turn potentially prolonging its availability for use as PPE. When making masks to protect PPE:
1) Lighter colors are better because they make it easier to see soiling
2) Use no more than 2 layers for this as no filtration is needed – the goal is protection from soiling, only
3) Ensure coverage if using over an N95 (these come in several sizes and from different manufacturers)
4) Fit is important, and ties that go around the back of the head are preferred
5) No latex should be used in designs for clinical settings – do not use elastic.
6) Using different colors on the front (outside facing; lighter is better) and back (inside facing) part of the mask is ideal so that the sides can easily be recognized.
From this excellent OSCMS review of patterns
The following website has an excellent discussion of what materials are best.
“Bottom line: Test data shows that the best choices for DIY masks are cotton t-shirts, pillowcases, or other cotton materials.
These materials filter out approximately 50% of 0.2 micron particles, similar in size to the coronavirus. They are also as easy to breathe through as surgical masks, which makes them more comfortable enough to wear for several hours.
Doubling the layers of material for your DIY mask gives a very small increase in filtration effectiveness, but makes the mask much more difficult to breathe through.”
- Can we use poly / cotton?
YES! It appears cotton blend works well – Dish towels even better!!