CMYK Printing: Subtractive Color, Halftoning, and Color Management

All flashcards

What is the CMYK color model?

CMYK is a subtractive color model used in color printing. Its four components are cyan, magenta, yellow, and black, with K referring to the key plate.

How does subtractive printing differ from additive RGB?

CMYK inks absorb light reflected from a light substrate, which supplies white. RGB displays emit light: combining red, green, and blue produces white, while no emitted light appears black.

What is halftoning?

Halftoning, or screening, varies the size or spacing of small ink dots so that they visually blend into tones and colors between the inks' full-strength colors.

Why is black ink added to CMY printing?

Black ink makes text and outlines sharper, provides more consistent dark tones, reduces the need for large amounts of colored ink, can shorten drying time, and is often more economical.

Why are ICC profiles important for color conversion?

ICC profiles describe how devices reproduce color and help a color management system map between device-dependent RGB and CMYK gamuts, taking account of the devices and conversion choices.

Quiz questions

1. What do the letters CMYK represent?Answer: Cyan, magenta, yellow, and black (the key plate).
2. Why is CMYK described as a subtractive color model?Answer: Its inks absorb parts of the light that would otherwise be reflected from the substrate.
3. How does halftoning make a region appear to have 20% magenta coverage?Answer: It arranges small magenta dots so they appear as a lighter pink tone at normal viewing distance.
4. What is one practical advantage of using a black key plate for text and outlines?Answer: It can produce sharper details than building them from three overlapping colored inks.
5. Why should RGB-to-CMYK conversion use color management rather than a universal fixed formula?Answer: Device characteristics, gamuts, rendering intent, and printing effects affect the result, so ICC profiles help guide the conversion.