Platering: An Obsolete Banknote Production Processby Franklin Noll on 07/30/20
Here's an example of an obsolete banknote printing process. The men in the photo are operating a Platering Press, which basically ironed sheets of currency to take out rinkles.
In the days of wet intaglio printing, sheets were repeated moistened before being printed. And, when you are using currency paper that is 75% or 100% linen, a lot of wrinkes develop as anyone who owns linen clothing knows. So, finished currency sheets had to be ironed smooth after printing.
Today's dry printing avoids this problem, and we no longer have Platerers.