Oki C9800hdn, Color Manual, Page: 20 / 100

1
1-20 Fiery Color Management
C9800 Color Guide - 20
Black Overprint
The Black Overprint option allows you to specify whether or not black text or
text/graphics—defined as RGB = 0, 0, 0, or as CMYK = 0%, 0%, 0%, 100%—
overprints colored backgrounds.
•
Text
—Black text overprints colored backgrounds, eliminating white gaps and
reducing halo effects or misregistration of colors.
•
Text & Graphics
—Black text and graphics overprint colored backgrounds,
eliminating white gaps and reducing halo effects or misregistration of colors.
•
Off
—Black text or text/graphics knocks out colored backgrounds.
N
OTE
:
PostScript applications may perform their own black overprint conversions
before sending the print job to the Fiery.
One example of how you might use this setting is with a page that contains black text
on a light blue background. The background blue color is CMYK = 40%, 30%, 0%,
0% and the black text is CMYK = 0%, 0%, 0%, 100%.
• With Black Overprint set to Text or Text & Graphics, the final text or text/graphic
portions of the page are overprinted, or combined with the underlying colors. Black
colors generated by applications (for example, RGB = 0%, 0%, 0%; CMYK = 0%,
0%, 0%, 100%) are printed using the maximum amount of black toner allowed by
the calibration curve. This means that black text and line art will not exhibit
halftone artifacts (as long as the printer is calibrated correctly). There is no transition
in the cyan and magenta toners, and the quality of the output is improved since it
will not show artifacts near the edges of the text or text/graphics. The option also
works with text defined in the RGB color space, that is RGB = 0, 0, 0.
• With Black Overprint Off, the border of the text or text/graphics is on an edge that
has cyan and magenta toners on one side (outside the text) and black toner on the
other side (inside the text). This transition may cause visible artifacts because of the
practical limitations of the printer.