Blanket

A rubber-faced sheet onto which ink is transferred prior to that ink being transferred to the sheet to be printed. The process 'offset' is so called because the ink is picked up by the blanket from the inked plate and then 'offset' or transferred onto the paper.

Bleed

When an image or design goes right to the edge of the printed sheet. The job is printed on oversize paper stock and the page's design extends around 3-5mm beyond the intended page size. The bleed is then trimmed off in the finishing process.

Calibration

The setting of computer system components to a standard which will produce the same colour results on each unit. Colour calibration is necessary on display monitors to achieve the same colour results on the printed output.

Camera Ready

An outdated term meaning artwork that doesn't need further alterations by the printer. The artwork was then used to make the printing plates via a photographic process, hence the term camera ready.

CCD

Charged Coupled Device. Light-detection device used in many scanners, digital cameras, and video cameras that generates electrical current in direct proportion to how much light strikes areas of the sensor. A CCD array is an arrangement of CCD sensors mounted in close proximity that allows for the simultaneous capturing of many pixels with one exposure.

Cloning

The process of sampling one area of an digital image to cover unwanted areas, e.g. replacing scratches with surrounding background to re-touch the image.

CMYK

See Four Colour Process.

Coated Stock

A printing paper or card manufactured with a transparent, smooth layer added to one or both sides that changes the look of the final printing. Coatings are normally defined as gloss, semi-gloss or matte surfaces.

Color Proof

A colour sample that attempts to represent the final printed image that will result when a piece is offset printed. Colour proofs can be generated from film separations prior to using the separations to make printing plates.

Continuous Tone

An image in which the subject has continuous shades of color or grey without being broken up by dots. Continuous tones cannot be reproduced in that form for offset printing but must be screened to translate the image into dots.