I'm new to modelling organic 3d shapes (I'm using Fusion 360's 'form' workflow), so I was happy to see my first 3d printed prototype masks are fairly good fits to my face.  I think the biggest difficulty of this project is designing a small number of different masks that will be both effective and comfortable for a large variety of people.

Currently, I'm 3d printing shells roughly 0.050"/1.2mm in thickness to test the geometry, with an eye towards vacuum-forming using similar thickness of stock. 

I've also done a first pass attempt at vacuum forming using my 3d printed prototype as a form (ultimately, I'll be CNC routing a 'proper' mold in MDF once I'm ready to commit to a design).  I don't have the right material on hand, and I don't have the best setup (as evidenced by the creases), but I've confirmed that the geometry should be moldable, as I intended.

For the time being, I'm just drilling holes for the elastic bands in the rim.  Once I get a more certain feeling for where they should go, I'll design in some ears to keep the gasket un-disturbed.