Following MDR's comment - in my career in the print / graphic arts business, I encountered 3 basic kinds of film output devices; color (transparency or print), black and white film continuous tone (like the film we develop), and screened film (as in screening patterns to achieve the look of grays, for printing).
Eventually, I think the continuous tone (known as "contone") plotters were discontinued for practical reasons. Many service bureaus still have screening film plotters, but the industry is slowly moving toward an all digital workflow.
Ralph - pm me and we can continue further if you wish, I think we are outside of scope here. Why do you want to know?
