The montana mask was created by longliveyoursmile.com they released this file they are using to help with the n95 mask shortages. I have printed and tried it out. They fit quite well. You can use dish rags, tshirt material, paper towel or anything you can think of. You can use the n95 paper masks and cut them into about 6 pieces to get more uses out of one mask. I used 4 layers of blue automotive shop towels just to try it out.
I also scaled one 95% for my wife that fit her well, Included file.
I have also included a file to create 4 masks if your printer is large enough.
Printer is a Creality CR-10
1 mask takes appx 3hr 30min