PRODUCTION
VARIABLES (I)
"Good
printing means controlling an array of production variables more complex
than anything known to most other kinds of manufacturing."
Paper is always a question mark.
There can be defects and
inconsistencies in sheet and roll stock (e.g., flaws that cause web breaks).
Humidity, temperature, and dirt can reduce the "runnability" paper.
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 "smashed."
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