DIY washable masks with removable filter
While DIY masks are not as effective as surgical or N95 masks* in preventing the spread of COVID-19, some doctors and other health care professionals are wearing them over the top of the higher-tech masks to increase durability. And use of these DIY masks, by lower risk populations, free up N95 masks for health care professionals and others who are at high risk.
Furnace filters have giant surface areas so you can cut at least 30 disposable fitlers if not more out of a single filter.
Also at filtration merv 13 (mpr 1900) it can block 98% of sneeze droplets and at merv 16 it can block 96% of virus sized particles.
According to the United States National Library of Medicine National Institute of Health, the Coronavirus nominally has a particle size of 0.13 microns: source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4369385/
Here's a chart for all the merv levels.
Amazon still has tons of next day shipping furnace filters available.
Search the appropriate merv or mpr level and you'll quickly find them.
Here's the DIY mask:
https://twin-cities.umn.edu/news-events ... g-covid-19
https://drive.google.com/file/d/1CI8AJz ... Qfl9a/view
If that's too daunting here's a video tutorial with another less efficient mask.
should help you make the first one.