Design Context: OUGD504 - Design For Print: Colour Systems

CMYK

The CMYK color model is a subtractive color model, used in colour printing.
CMYK refers to the four inks used in some color printing: cyan, magenta, yellow, and key (black).
The "K" in CMYK stands for key because in four-color printing, cyan, magenta, and yellow printing plates are carefully keyed,or aligned, with the key of the black key plate.
CcMmYK, sometimes referred to as CMYKLcLm or CMYKcm, is a six color printing process used in some inkjet printers optimized for photo printing. It extends the customary four color CMYK process, which stands for Cyan, Magenta, Yellow and Key (black), by adding light cyan(lower case c) and light magenta (lower case m). The light cyan and light magenta inks are essentially a washed out version of the cyan and magenta inks.
The most noticeable result of using light cyan and light magenta inks is the removal of a distinct and harsh half-toning dot appearance that appears in prints that use light shades of cyan or magenta on the pure CMYK ink configuration.

RGB

The RGB colour model is an additive colour model in which red, green, and blue light are added together in various ways to reproduce a broad array of colours.
In computers, the component values are often stored as integer numbers in the range 0 to 255, the range that a single 8-bit byte can offer. These are often represented as either decimal or hexadecimal numbers.

Grayscale

A grayscale image is an image in which the value of each pixel is a single sample. It carries only intensity information.
Images of this sort, also known as black-and-white, are composed exclusively of shades of grey, varying from black at the weakest intensity to white at the strongest.

Pantone

The Pantone Colour Matching System is largely a standardised colour reproduction system. By standardising the colors, different manufacturers in different locations can all refer to the Pantone system to make sure colors match without direct contact with one another.
A majority of the world's printed material is produced using the CMYK process, and there is a special subset of Pantone colors that can be reproduced using CMYK. Those that are possible to simulate through the CMYK process are labeled as such within the company's guides.
However, most of the Pantone system's 1,114 spot colors cannot be simulated with CMYK but with 15 base pigments mixed in specified amounts.
The Pantone system also allows for many special colors to be produced, such as metallics and fluorescents.
Pantone colors are described by their allocated number.

Spot Colour

A spot colour is a specially mixed ink using in printing.
Spot colour inks include some specialty inks such as metallic and fluorescent.
Unlike CMYK or process colour which creates colors by laying down layers of just 4 specific inks, spot colors are pre-mixed and you use one ink for each colour in the publication.
You can also use tints of a spot colour to get the appearance that you're using more colors without the expense of additional inks.There are different brands of spot colour inks.
The dominant spot colour printing system is PANTONE. The Pantone Matching System or PMS consists of over 1,000 colors of ink.
Other spot colour systems include TOYO, DIC, and ANPA.

Half-tone

Halftone is the reprographic technique that simulates continuous tone imagery through the use of dots, varying either in size, in shape or in spacing.
Halftone can also be used to refer specifically to the image that is produced by this process.
Where continuous tone imagery contains an infinite range of colours or greys, the halftone process reduces visual reproductions to an image that is printed with only one colour of ink, in dots of differing size.
This reproduction relies on a basic optical illusion—that these tiny halftone dots are blended into smooth tones by the human eye.