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Printing techniques
In contemporary offset lithographic printing, digital files from desktop computers are
output to an imagesetter, which creates film separations. The film is used to make a
prepress proof
, which is an accurate predictor of the final print job, allowing an
opportunity to make corrections before going to press. Once the proof is approved, the
printer makes plates from the film and runs the print job on the press.
With a DocuColor 40 CP, you simply print the file. The DocuColor 40 CP processes
the
PostScript
information in the file and sends four
bitmaps
(one each for cyan,
magenta, yellow, and black) to the print engine. The ease of DocuColor 40 CP print-
ing makes possible experimentation that would be too costly on press, allowing unlim-
ited fine-tuning of color and design elements.
Halftone and continuous tone devices
Halftoning is used in offset printing to print each process color at a different intensity,
allowing millions of different colors to be reproduced using only the four process
colors. Depending on the required intensity of a given color, ink is placed on paper in
dots of different size. The grid of dots used for each ink color is called a screen.
Halftone screens are aligned to unique angles designed to eliminate interference
patterns called
moiré
that can arise with halftoning.
Imagesetter
Film
Proof
Press
Desktop
Print run
computer
Desktop
computer
Print device
Color prints
