COVID-19 MASK Coronavirus - Cotton Pads, Easy-To-Print, No Support
Original design
https://www.thingiverse.com/thing:4245757
I made a grid in the shape of a honeycomb, because it lets air through much better, and I also placed the grid only where it should let air through.
This is a very good mask design, because it completely covers the filter from external influences, as well as air pollution from the side opposite from potential danger.
The only drawback of this mask is that the filter area is not fully used, I have a mask design with a lower level of protection, but using a larger filter area.