The printer doesnt matter as long as you can fit the massive 6 1/4\ x 8 1/14\ (70cm x 210cm) object.  You can print with rigid ABS, PLA, a flexible Nylon, or anything that will easily hold its shape. Use a 100% infil as you will be clamping this part.  The finished print needs to have at least a shore A hardness of 60 or more. I produce each mask at $0.98 and the rubber for the mold is $12.64If you think this idea is worth spreading, please rate!  If youre going to give my efforts a single star, please have the courage to tell me what I could do better.Youre not making a mask with the printer.  Youre making a two-part container to cast molds(from ecoflex or moldstar) to make masks.  Then pour masks out of Smooth-ons 61D or Task 8(if you need the mask to survive an autoclave).  This sounds like a lot of work, but there are cumulative returns on your effort!  That means youll produce masks exponentially.  Create N-1 masks per hour where N= the molds youve casted.  On Apr 20th, I created 50 masks.  On April 21st, I was able to increase production to over 100/day while still working and only using my 15 min breaks, lunch hour and some time outside of work.For example, if you poured 15 molds, you can create 14 masks an hour or  168 masks per day without a 3D printer.  If you 3D print five mold masters, you can cast five molds at a time!  This will scale more exponetially than the virus is infecting people!  Go team Humans!Note that 61D cant go through an autoclave, but in talking to hospitals, theyre just using bleach water here in Montana.  Smooth-On recommends using Task 8 if you want your mask to survive the autoclave.  Bleach water has been proven effective on a ABS FDM version of this mask via a culture test.  Culture tests are a good start... but they dont indicate the irradication of a virus.  Having said that... bleach kills over 99.99% of viruses and Covid19 is proven to be one of them. 61D has much lower porocity than ABS FDM.  It should perform far better when washed with bleach water or even wiped with a Saniwipe.  If you pour your masks with Task 8, it will be able to withstand an autoclave.I recommend using long clamps to hold the molds together.  I stop at sections of 15 molds because my clamps arent long enough.    15 molds per clamping might be a good number to stop at anyway.