Paper from Science linked below, but here is the key figure. A wide range of masks work very well in reducing droplets including
-Fitted N95
-Surgical
-Poly/Cotton
-Swath
-and many more...
However, fleece masks appear to be worse than no mask (researchers speculate that the fleece breaks up the droplets into smaller droplets).
I should also point out that the main aim of the paper was to describe a relatively simple and inexpensive testing system for evaluating masks. This is just one piece of the puzzle with regard to masks.
"Droplet transmission through face masks. (A) Relative droplet transmission through the corresponding mask. Each solid data point represents the mean and standard deviation over 10 trials for the same mask, normalized to the control trial (no mask), and tested by one speaker. The hollow data points are the mean and standard deviations of the relative counts over four speakers. A plot with a logarithmic scale is shown in Supplementary Fig. S1. (B)The time evolution of the droplet count (left axis) is shown for representative examples, marked with the corresponding color in (A): No mask (green), Bandana (red), cotton mask (orange), and surgical (blue – not visible on this scale). The cumulative droplet count for these cases is also shown (right axis)."