Two masks with 750 thread count cotton

Mid 2021 update:  High thread count cotton and/or multi-layer polyester satin isn't a good choice for high filtration masks. They're not breathable enough at mid filtration performance. And additional layering to get to hight filtration still only decreases breathability further. With that they get hot and uncomfortable as well as giving your chest muscles a good workout.

Context: the Chicago/Argonne fabric study (Konda et al) via "ACS Nano" picked 600-thread Wamstutta cotton (not available in the UK) and a fancy chiffon (that's not widely available).

So this is the RagMask Max design with an outer layer of 750 thread count cotton (from "Marks and Spencer" sheets) and a liner of a single layer of he Viceroy satin (polyester satin, from sheets - bought from Amazon). As I knew already the 750-thread cotton is very hard to breath through, so I've been experimenting with retainers and stiffeners to force cupping again. One mask with two thin plastic stiffeners each side sewn in to the mask between the layers. And one with zip tis sewn on after the mask was made.

Both are fairly ugly masks, but breathability is back compared to alternates for the same two fabrics. I might try another permutation tomorrow.

Note: I've previously drilled into the ACS data - https://fu-cv.blogspot.com/2020/06/playing-with-argonnechicago-fabric.html

June 30th update: I've now worn the top one (sewn in stiffeners) for three hours straight. This was inside at 12° C (53.6° F). I was sawing wood, flooring boards and plaster/drywall boards with hand and circular saws . The fabric was fine, my ears were fine (versus ear-elastic which can cut in after a while), but my nose suffered under the nose wire after two hours.

July 2nd update: See mask #3 in this series with "ribs" sewn in - https://fu-cv.blogspot.com/2020/07/high-filtration-cloth-mask-with-ribs.html