Here are some articles that include test results for some materials:
Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic?
Article (PDF Available) in Disaster Medicine and Public Health Preparedness 7(4):413-418 · August 2013 www.researchgate.net/publication/258525804_Testing_the_Efficacy_of_Homemade_Masks_Would_They_Protect_in_an_Influenza_Pandemic
Using blue shop towels in homemade face masks can filter particles 2x to 3x better than cotton, 3 clothing designers discover after testing dozens of fabrics www.businessinsider.com/homemade-mask-using-hydro-knit-shop-towel-filters-better-2020-4
btw some shop cloths are made with latex so check before using if this is an issue for you or someone you are making them for!
Testing Shows Type of Cloth Used in Homemade Masks Makes a Difference, Doctors Say newsroom.wakehealth.edu/News-Releases/2020/04/Testing-Shows-Type-of-Cloth-Used-in-Homemade-Masks-Makes-a-Difference
UF Health anesthesiology team devises respirator mask made from existing hospital materials ufhealth.org/news/2020/uf-health-anesthesiology-team-devises-respirator-mask-made-existing-hospital-materials
The innovative mask uses Halyard H600 two-ply spun polypropylene that cannot be penetrated by water, bacteria or particles. It blocks 99.9% of particulates, making the masks about 4% more effective at blocking particulate material than the N95 masks, according to Bruce Spiess, M.D., a professor of anesthesiology in the UF College of Medicine, who made that calculation based on the manufacturer’s specifications.
their patterns here:
Mask Alternative: The University of Florida Health’s department of anesthesiology has developed 2 prototypes for masks that can be produced in large quantities using materials already found in hospitals and medical facilities. anest.ufl.edu/clinical-divisions/mask-alternative/
How to safely put on and remove mask without contaminating yourself:
How to Make Your Own Face Mask (only 2 materials needed!) – bandana and hair elastics
h/t shallah