Researchers at Cambridge University tested a wide range of household materials for homemade masks. To measure effectiveness, they shot Bacillus atrophaeus bacteria (0.93-1.25 microns) and Bacteriophage MS virus (0.023 microns in size) at different household materials.
They measured what percentage the materials could capture and compared them to the more common surgical mask. (See their results in the image above).
More information about fabric effectiveness, if doubling the layer helps and more here.
Credit: Smart Air