Listed on https://stop-postillons.fr/
This version is for pure research and development. Hoping it will inspire people.
Use at your own risk.
Obviously tissue masks are easier to mass-produce, but require TISSUE.
This mask is lightweight and can be 3D-printed with various materials. I suggest PLA.
You can 3D-print AT ANY SIZE because IT IS SCALABLE AND CUSTOMIZABLE.
In the slicer you can stretch it on the 3 axis.