A few years back I decided to try making a Russian apartment building out of foamcore. It turned out quite nice - not that there is really much to a Russian apartment building! But to make it just a little bit nicer, I found some Russian propaganda posters online and printed one out on my colour printer. Getting it the right size was a problem, as for it to be actual scale made it too small to recognise what was on it, so a happy middle goprund was reached with the poster being just a little larger than scale.
But the scale issue was one using preconceived notions that everyone made posters the same size. Looking at the picture above that I recently found in the book Absolute War, I now think my poster may have been way too small to be proper scale! Those Russians certainly knew how to make their point; with HUGE posters.