Xerox 4.2 - Manual (Page 24)

RGB Saturation and Pure Rendering Intents
The Saturation intent also benefits from the new GCR
strategy and enhanced gamut mapping methods,
offering more saturation throughout the CMYK source
space. More dark, saturated colors are available with
this release.
RGB Perceptual Rendering Intent
The Perceptual Rendering Intent for this release yields
more accurate tone scale reproduction. The
Perceptual Intent also offers the new, patented GCR
strategy improving dark color rendition.
Gamut mapping to the Perceptual intent maintains L*
for high chroma source RGB calls, where the Relative
Colorimetric intent was focused on balancing L* and
chroma information.
R=G=B=0 to K only
R=G=B = 0 maps to K (Black) only for this release.
Billing for R=G=B=0 accurately reflects the K only
charge.
Previously, R=G=B=0 (monitor black) introduced a
small percentage of C, M, or Y.
20 DocuSP 3.8 and 4.0 to 4.1 Differences Document