Advice on creating resin molds for vacuum forming. Replica Phantom of the Opera mask

[Kaito3Designs]

I create sculpturally accurate Phantom of the Opera mask replicas but my main caveat is that I 3D print while the real props are vacuum formed. I am looking to get into vacuum forming but the main thing that is stumping me is what material to use to create molds that will repeatedly be used for many pulls. So far in my research I've seen that resin is a reliable choice. Could you guys recommend me some resins that are affordable and not overly difficult to work with?

I'm planning to create a silicon negative from a smoothed out 3D print and filling the negative with resin.

 

[division 6]

For vacforming you want to use Ultracal stone, not resin.

 

[Mr Mold Maker]

If your printer is big enough or you’re willing to use a service, you can vacuum form right on top of a resin printed buck. I did replica scream, Jason, and the Halloween End’s Allyson cat mask. All vacuum formed from 3D printed bucks with 3 or 3.5mm walls and they worked perfectly.
The great thing about this method is you can punch all the holes and design the flange digitally instead of having to clay it up, make a mold, drill the holes, etc.

If you’d prefer to go the molding and casting way you can produce a buck with ultracal but I believe there is a nationwide stone shortage in the US. If you’re not in the US you may be able to get something similar or dental stone.
As for resin.. Most filled resins should work, Repro One, 1630 from BJB, Task18 or Smoothcast 380 from smooth-on. Etc. You can even lay up a polyester or epoxy and fiberglass buck.