That's some question......coming from a Printer Guru............ Opera has file>print options>scale.....................I would think there is something similar in FF but cannot be more accurate as I don't have FF...
It works like Opera does on this but the sequence is File>Page Setup>Scale
Two options in Firefoxfile>page set up>format and options>scaleorfile>print preview>format and options>scaleIn both options the "scale" bit may be greyed out, to get it "live", uncheck it's neighbouring box "shrink to fit page"
Glad it's sorted - I just set out the route I use for doing it - habit I suppose. Still, I suppose a Guru does need to know ALL the ways to achieve peace and printing - that's what marks them out from us everyday wannabes!