A number of vapor tests have been done recently, and yes, the N-95 masks (without exhaust port) are the best protection, but are still in too short supply for all of us to have and use. The hospitals, clinics and dentist offices are still insisting that patient-facing staff who wear them make them last at least all day, if not for multiple days at a time. When they were used per-Covid, masks were discarded and replaced between patients in infectious situations (like with MRSA patients or immuno-compromised patients.)

Other masks that tested well (not quite as good as N-95) were surgical masks (the multi-layer disposable type) and cloth masks made of multiple layers of tightly woven cotton or cotton blend fabrics. Masks that did a poor job of keeping droplets from spreading were bandanas and the "gaiter" type or other masks made of fleece or knit fabric.

We wear 3-layer clothe masks for everyday use, we have several different styles, with different type of ties/elastic depending on how they will be used on a particular day. We also have a small supply of N-95 masks which we use when exposed to soil due to lung issues. We are safeguarding those to use in case one of us becomes ill.

It must also be noted that masks are ONLY effective if they cover your face snugly from above the nostrils to the chin so as little vapor escapes as possible. Also, a mask that becomes wet from your breath should be replaced with a clean, dry one as wet masks are not as effective. Discard the soiled mask or bag it for washing & wash or sanitize your hands after handling it. Reusable masks should washed very frequently by hand or machine. Air drying is fine - the soap & water kill the virus. After a day of errands or visiting with my kids/grands, we may have as many as 6 masks to wash.
Sue