Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4806441. I wanted a mask that would fit ME so I made one that follows the contours of a head model. Additional requirements were: - Fully parametric so I could make custom fit masks for other family members. - Enough filter area for easy breathing. - Minimal material use and quick printing with a .8mm nozzle and .32mm layer height. - Replaceable grilles for fun and artistic expression. - A design that works with hard or soft plastics.