An excellent Kodak documentary from 1958 can be seen on YouTube. It shows the production of monochrome roll film from beginning to end and reveals the chemical and mechanical excellence of the age. Looks to be a USA-made film but carries Dutch voice-over, hence English subtitles!
Marvel at the cellulose acetate film base production, the tons of silver used each weeks, emulsion making, film coating and the fiendishly complicated automatic spooling!