Found on the wilds of FB the credit is to Mrs. Anya Verheyens post below. It’s insanely smart to me. You can put a filter in the sleeve before you tie it on.

#wearamask Much of the confusion around masks stems from the conflation of two very different uses.

Hong Kong, only four confirmed deaths due to COVID-19 have been recorded since the beginning of the pandemic, despite high density, mass transportation, and proximity to Wuhan. Hong Kong’s health authorities credit their citizens’ near-universal mask-wearing as a key factor (surveys show almost 100 percent voluntary compliance).

Along with keeping our distance whenever possible and maintaining good hygiene, all of us wearing just a cloth mask could help stop this pandemic in its tracks.

Best explanations of masks and layers I've found so far.

Interesting way to isolate foreground of image with a lot of detail, such as strands of hair using layer mask. Need clean background to start, but interesting technique.