Homemade HEPA Filter Mask Instructions (Using HEPA Vacuum Bag)
Dec 11, 2020·There is a pattern similar to the above pattern on Pinterest. I have made over 100 of them and I made a pattern for the insert of the HEPA filter. Once you have made your mask, lay it flat on a piece of paper and trace it. Take 1/2 inch off the bottom of your tracing.