Flexography involves surface relief on a polymer plate i.e. something like a rubber stamp. It is usually a high volume process (24", 300 ft./min) but resolution is limited and there is rigidity of the plate and an Anilox roller to cope with.
Because flexographic printing applies the medium using a raised pattern that is flexible it is somewhat tolerant of surfaces that are not level. Poly IC use it for reel to reel pilot manufacture of polymer flexible transistor networks TFTCs.
See the IDTechEx report Introduction to Printed Electronics