"Good printing means controlling an array of production
variables more complex than anything known to most other kinds of
• Paper is always a question mark.
• There can be defects and
inconsistencies in sheet and roll stock (e.g., flaws that cause web
• Humidity, temperature, and dirt can reduce the
• The "weather" in the pressroom could be different from
the "weather" where the paper was stored. Sheet edges become wavy or
tight as moisture is absorbed or lost at press-side. This can threaten
registration. Paper should always be "conditioned" before running.
• Every litho press run is still a chemistry experiment.
• Ink and fountain problems: scratch-off or rub-off from
poor mixing... "scumming," i.e., adhesion in non-image areas...
"emulsification" turns ink to sludge when the pH of the fountain
solution is too acidic...algae in the water: yuck!
• Plates can fracture or become scratched; blankets get