Make your own mask, as good as an N95, and washable too/ Consumerlab.com

The following discussion comes straight from consumerlab, which is a subscription service.  This is the best information I have found for producing a washable, highly effective mask that can protect both the user and everyone else nearby--Meryl
Here is their August 2020 update.

Question:
How can I make a mask that is as good as a surgical mask or an N-95 mask? 
 
Answer:
If made with the right household materials, you can create a mask that may be as effective as a medical mask or even an N-95 respirator, according to several laboratory studies. Masks can be used alone or, for increased protection, particularly for the eyes, with a face shield. 

How materials compare in blocking coronavirus 

The first study, from the University of Illinois at Urbana-Champaign, found that many household fabrics can be as effective as the material in surgical masks for blocking droplets the size of the COVID-19 (SARS-CoV-2) coronavirus. The blocking efficiency of a commercial medical mask was found to be 96.3%, while the blocking efficiency of a used dish cloth (85% polyester and 15% nylon) was slightly better -- 97.9%. In addition, most household fabrics were more breathable than the material in a medical mask. The dish cloth, for example, was twice as breathable as the medical mask (Aydin, medRxiv 2020 --preprint). (See the CDC website to learn how to make a cloth face covering.) 

A study at the University of Chicago and Argonne National Laboratory found that tightly woven, high-thread count cotton (600 thread-per-inch (TPI) sheet by Wamsutta) was more effective in filtering large droplets (similar to larger-sized SARS-CoV-2 droplets) than loosely woven cotton with a lower thread count (quilters cotton, 80 TPI), while fabrics with an electrostatic charge (such as silk and chiffon) were best for blocking aerosols -- the smaller sized droplets that remain suspended in air for extended amounts of time. Using layers of both fabrics, together, was most effective for blocking both large and small droplets. For example, two layers of 600 TPI cotton fabric had a large particle and small particle blocking efficacy of 99.5% and 82%, respectively, but one layer of 600 TPI cotton combined with two layers of chiffon (90% polyester, 10% spandex from Jo-Ann Stores) had a large particle and small particle blocking efficacy of 99.2% and 97% -- which is nearly as good as a properly-fitted N95 mask for blocking large particles and better than the N-95 with respect to small particles, of which only 85% are blocked by an N-95 mask). The researchers also found that small holes or leaks around the edges of the fabrics could decrease the blocking efficacy by 50% or more, and emphasized the importance of a good fit (snug and without gaps) (Konda, ACS Nano 2020). [Note: An illustration in the study shows the electrostatic layer of fabric as the inner layer when fabrics were combined. However, ConsumerLab contacted the author of the study who suggested that electrostatic fabric (such as chiffon) may be best used as the outer layer of the mask to avoid humidity from the nose or mouth, which could interfere with the electrostatic properties, but emphasized that was his suggestion, not something that was tested in the study.] 

How to reduce air leakage around a mask 

A way to reduce air leaks was suggested by a study, at Northeastern University in Boston, which showed that pulling an 8 to 10-inch tube of nylon (cut from a queen-sized nylon stocking) down over a regular mask and to the top of the neck. This significantly prevented air leakage around the mask and improved particle filtration efficiency, making the combined masking nearly as effective as an N-95 respirator which, unlike a medical mask, has an electrostatic charge and is specifically designed to prevent air leakage (Mueller, medRxiv 2020 --preprint; Godoy, NPR.org 4/22/20). 

How to clean a cloth mask 

Cloth masks can be washed in a washing machine. They can also be cleaned using heat, but a washing machine is preferred.