This is play money, like Monopoly Money and is not based of the US dollar but is based of of the Canadian Bill of the 1920s era. A back will eventually be provided, but printing each bill ($1, $5,$10,$20,$50, ect) in a different color paper should suffice for most gaming needs.
Use them as you want for RPGs, or playing poker in a 1920s vibe. This first one is rather low res but fine enough for printing, they should be bigger than modern bills as that's how it was in the day.
Seal is from Propnomicon propnomicon.blogspot.com/