So I made that mask (see MOAG) and part of it used gold cardstock.
You can see the product page here, though i am not sure it’s available anymore:
What’s interesting about it is that it just can’t cut all the way through. The metallic layer appears to be actual metal foil. This led to an interesting method:
Cut from the back, (350/50/1x) and you get perfect score lines. You can then punch it out, it peels out almost like you’re opening a really easy pull-top can. The end result is a perfect piece, no scorching, no char.
You can see the scores from the front side.
You pop it out and voila.
There are other lighter scores and engraves on the back so help with assembling the mask. (1000/10/225lpi/1x engrave, 350/4/1x fold scores)
If you can find it, this stuff is great.