At the risk of reigniting The Great Mask Debate, Duke University has published a study regarding what types of masks work best. They had a speaker wear mask, talk into a box and with the use of a laser record the escaping droplets by camera.
Best - N95 (duh)
2nd Best- 3-layer surgical
All decent - various cotton masks. The poly/cotton mask did the best of the group. These are what Disney has been making.
Worst- Bandanas
Worse than Useless - Gaiters. They actually break up the larger drops into smaller droplets making it
worse than wearing no mask at all.
advances.sciencemag.org