Centre Spread - middle two pages of a stapled magazine. Often sold to premium advertisers or used as an editorial feature.

Circulation - The distribution of newspapers, magazines, and other print publications

Circulation - Can vary according to context. Usually, the number of copies of a periodical or magazine distributed or sold.

CMYK - Four colours (cyan, magenta, yellow, black) used in the standard printing process. In theory, CMY should produce black, but in practice the black ink is needed for depth and contrast.

Coated Paper - paper coated with a mixture of china clay, latex or other materials to give a smooth finish for printing. Usually used for magazines.

Colour Depth - The number of colours used in a picture file. The more bits available for each pixel, the more colours available: 4 bits for 16 colours; 8 bits for 256; 16 bits can generate 65,536; 24 bits can describe almost 17 million, more than can be distinguished by the human eye.

Colour Proof - Representation of how a colour page will be printed. Proofs may be made using the printing film or from the digital page files.

Commission - Pay to a magazine's advertising staff or agent for bringing in business. Often a percentage of salary for staff once targets met

Consumer Magazines - Titles aimed at the general public covering a broad range of topics.

Consumer Specialist Magazines - Titles aimed at a targeted audienec about a specific topic, for example, hobby magazines.

contract publishing - Publishing magazines under contract to a non-publishing company, for example, IKEA.

Copy - Content, written text.

Cyan - Sky-blue ink used in the CMYK colour printing process.