My college summer job was being a mechanical engineering intern at Continental Can’s flexible packaging plant in Paoli, PA. The whole process of making custom printed paper and lined paper bags was amazing like that. The enormous rolls of paper, the unwinders, the flying splices when one roll was exhausted and a new roll moved into position! The machines that folded the paper bags which was a one-bag-at-a-time process. Wow. All for something as prosaic as a paper bag.
500 pound bales of pulp drop into the hydropulper every few seconds. If you ever need to dispose of a body, a paper mill has about 100 ways to kill you and there would be no trace. Even your bone fragments get re-ground until the fines put you into the paper. The whitening and brightener bleach your blood n guts into fats scraped off as a foam in the wastewater recirculating process. (It no longer goes out to a river to flow away) The de-wetting water is all recycled. The fresh makeup water merely offsets the Yankee Dryers steam flow in drying the sheet.