Xerox 2000 manual Crd

glossary

Colour rendering
dictionary	A lookup table in PostScript that describes how to map colour from one
	device to another. Also called CRD.
Colour separations	A full colour image broken down into a series of single colour images of
	the primary printing colours. This is most often the four process colour
	images (CMYK), but may also include spot or specialty colours.
Colour space	The range of colours that can be seen, displayed or printed. Also called
	gamut.
Compression	A technique to reduce the size of image files, reducing storage and
	transmission requirements. There are two categories of compression:
	lossy and loss-less. Lossy compression means that some data is
	permanently removed during the compression, leading to a loss of
	quality (the degradation of quality is linked to the amount of data
	removed). Loss-less files are larger, but retain all original image data.
Consumable	Any material, such as paper, ink or toner, that is used up (or consumed)
	during the printing process.
Continuous tone	An image that has an unbroken range of intensities, as found in black
	and white photographs. Continuous tone images have not been
	screened, and contain gradient tones from black to white.
Contone	Short for continuous tone, an image that has an unbroken range of
	intensities, as found in black and white photographs. Continuous tone
	images have not been screened, and contain gradient tones from black
	to white.
Contract proof	A proof made as a true indicator of the final printed product. It is used
	to secure final approval by the customer before a job is printed.
Conventional angle set	In the colour separation process using AM screening, there are four
	screens made of dots (one for each process colour). To avoid Moiré
	patterns when two or more screen grids are combined, a rosette pattern
	is used. To create this pattern, the four halftone screens must be placed
	at different angles. The conventional angles are: Black at 45º, Magenta
	at 75º, Cyan at 15º or 105º, Yellow at 0º or 90º.
Conventional printing	A common term for offset printing.
Copies per minute	A term commonly used with xerographic printing for measuring print
	speed.
cpm	Short for copies per minute.
CRD	Short for colour rendering dictionary.
Creep	A term used to describe how the gutter margin varies from page to page
	when large signatures are folded and trimmed (the printed area moves
	slightly with respect to other pages). Adjustments are made at the DFE
	to correct for creep.
Crop marks	Lines printed in the margins of a sheet to indicate where the sheet
	should be trimmed.

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