A handful of the enormous quantity of postcards that were printed up for the fair.
In the years leading up to the PPIE, there were postcards printed up encouraging people to choose San Francisco as the host city. During 1915, there were many postcards showing images of the various buildings, palaces, and statues. Also, advertising postcards were printed up by the various businesses and exhibitors at the fair, promoting their product/etc. And then of course there were the countless other general San Francisco and California postcards printed up that mentioned the PPIE as a tie-in.