Xerox 5252 User Manual

DocuColor 5252 Operator Manual

2-9

About color  pr inting

There are limitations to achieving the exact colors when 
converting from RGB (for video display) to CMY (for 
print). For example, CMY pigments aren’t capable of 
producing consistent black or gray tones. 
In cases in which the three ink or toner colors overlap 
heavily, software applications automatically vary the 
percentages of cyan, magenta, and yellow to enhance 
image quality and improve printability. This technique is 
known as undercolor removal, or UCR, in which black ink 
is used to replace cyan, magenta, and yellow ink in 
neutral areas only (that is, areas with equal amounts of 
cyan, magenta, and yellow). This uses less ink and 
provides greater depth in shadows. UCR is generally 
used for newsprint and uncoated stock
Another form of undercolor removal is called Gray 
Component Replacement (GCR). To compensate for the 
neutral or grey tones created during the conversion of 
RGB to CMYK, black ink replaces portions of cyan, 
magenta, and yellow ink in colored areas, as well as in 
neutral areas. GCR separations tend to reproduce dark, 
saturated colors somewhat better than UCR separations 
do, and they maintain gray balance better in print.