With so many Joes being ordered to cough up their own facemasks (no pun intended), there is an official line that said ersatz booger shields should be as uniform as possible.
U.S. Army Forces Command (FORSCOM) guidance on masks
However, to get the point across to the cammie-clad masses and single out the E4 Mafia, other bases have gotten a little more specific to include a “don’t be this guy” section.
Fort Stewart Hunter Army Airfield, Re: masks
U.S. Army Garrison Stuttgart, Re: mask
Of course, since I have been using my own bandana-derived mask, I rather look more like an Old West desperado.
Or perhaps the Avenging Shadow!
The Masked Rider (May 1934) Western Pulp: The Avenging Shadow
As someone who took CBRN classes back when it was just called NBC, and has had the joy of fumbling with those BS canteen cap straws through the old M17 mask, you know that I have some decent stuff set to the side for the who-knows-what. However, not wanting to start burning through the small stack of sealed filters for my M40s, or wear my shop respirator to the local produce stand and look like Bane from Batman, I sat around and coughed up an ersatz bandana mask.
Basically, using about a three-foot length of 550 paracord, a stack of coffee filters, and an oversized bandana, it is simple and wears well. Just fold the filters inside, knot the two ends, pass the cord through in a horizontal line with the two ends loose. To put on, slip it over your head with the horizontal paracord to the back around your neck and pull the loose ends tight across the top of your scalp, then tie in place. Pop a cap on to help keep in place and remember that glasses/shades are your friends these days.
Boom. The bonus of using a single piece of cord wrapped A) around the back of your neck and B) over the top of your head, holds the mask tight both horizontally and vertically and keeps from having your ears rubbed raw. If you don’t have paracord, a shoe/boot string works just as well.
The above is slightly more engineered that your typical expedient mask but involves no sewing or real skill to make, and most guys have the three ingredients around the house.
For reference, here is the Marine Corps guidance on making facemasks from an old skivvy shirt:
Meanwhile, in the Army…