My first job in the industry was cleaning screens at a flat stock shop.
I cleaned on a big table, covered with a stack of billboard sectional prints, white side up.
It was one of my duties to pick out cleaning papers that by sheer luck had artistic merit. One of a kind prints created with various combinations of poster and enamel inks, dissolved hand cut amber film, and xylene and lacquer thinner.
These were presented every couple of weeks to a local interior designer who bought some, mounted and framed them, and passed them along for the big bucks.
