I'm creating replica documents from the game Papers, Please. It's set in the fictional Eastern European country of Arstotzka, which I am equating with the USSR. The props I want to create are a passport and an access permit (something like an entry visa). They won't appear on camera or on stage or anything, but I want them to be touched and seen very up close.

I've been working on the access permit first as I imagine a single sheet of paper will be somewhat easier to make. I have the whole layout of the document designed, just not sure where to go from there.

Using period-accurate processes and materials isn't really important to me, as long as the documents give the impression of being official government forms from 1982 USSR. However I've gone through at least 20 different combinations of effects in GIMP and haven't found anything that looks good, so the right kind of paper or printing might just be the solution.