About color printing
Adding and replacing gray to improve color
| UCRR | There are limitations to achieving the exact colors when | ||
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| converting from RGB (for video display) to CMY (for |
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| print). For example, CMY pigments aren’t capable of |
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| producing consistent black or gray tones. |
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| In cases in which the three ink or toner colors overlap |
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| heavily, software applications automatically vary the |
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| percentages of cyan, magenta, and yellow to enhance |
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| image quality and improve printability. This technique is |
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| known as undercolor removal, or UCR, in which black ink |
| No GCR | |||
| UCR | is used to replace cyan, magenta, and yellow ink in | ||
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| neutral areas only (that is, areas with equal amounts of |
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| cyan, magenta, and yellow). This uses less ink and |
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| provides greater depth in shadows. UCR is generally |
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| used for newsprint and uncoated stock |
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| Another form of undercolor removal is called Gray |
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| Component Replacement (GCR). To compensate for the |
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| neutral or grey tones created during the conversion of |
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| RGB to CMYK, black ink replaces portions of cyan, |
| Light GCR | |||
| magenta, and yellow ink in colored areas, as well as in | |||
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| neutral areas. GCR separations tend to reproduce dark, |
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| saturated colors somewhat better than UCR separations |
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| do, and they maintain gray balance better in print. |
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Medium GCR
Maximum GCR
2 About color printing
DocuColor 5252 Operator Manual |
