Glossary

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Dampers
In lithography, cloth-covered, parchment paper or rubber (bare back) rollers that distribute the dampening solution to the press plate or ink roller.
DDES
Acronym for Digital Data Exchange Specifications.
De-Inking
Process used to remove ink from waste paper to achieve an acceptable shade. This process principally uses water and detergents and is environmentally a relatively benign process.
Deckle
In papermaking, the width of the wet sheet as it comes of the wire of the paper machine.
Deckle edge
The untrimmed feathery edges of paper formed where the pulp flows against the deckle.
Deforestation
Large scale clearance of trees, either for the timber and/or the land. Major contributor to global warming, flooding and soil degradation.
Densitometer
In printing, a reflection densitometer is used to measure and control the density of colour inks on the substrate.
Density
The degree of darkness (light absorption or opacity) of a photographic image.
Descender
That part of a lower case letters which extends below the main body, as in "p".
Desensitiser
In lithographic plate making, chemical treatment to make non-image areas of a plate repellent to ink. In photography, an agent for decreasing colour sensitivity of photographic emulsion to facilitate development under comparatively bright light.
Developer
In lithographic plate making, the material used to remove the unexposed coating.
Die-cutting
The process of using sharp steel rules to cut special shapes for labels, boxes and containers, from printed sheets. Die cutting can be done on either flat bed or rotary presses. Rotary die cutting is usually done in line with the printing.
Die-stamping
An intaglio process for the production of letterheads, business cards, etc., printing from lettering or other designs engraved into copper or steel.
Digital colour proof
An off-press colour proof produced from digital data without the need for separation films.
Digital plates
Printing plates that can be exposed by lasers or other high-energy sources driven by digital data in a plate setter.
Digital printing
Printing by plateless imaging systems that are imaged by digital data from pre-press systems.
Digitised typesetting
In typographic imaging, the creation of typographic characters and symbols by the arrangement of black-and-white spots called pixels or pels.
Digitiser
A computer peripheral device that converts an analogue signal (images or sound) into a digital signal.
Dimensional Stability
Ability to maintain size; resistance of paper or film to dimensional change with change in moisture content or relative humidity.
Dioxin
A group of 75 chlorinated compounds. Dioxins are formed in a complex process, where chlorine combines with other additives during bleaching.
Display type
In composition, type set larger than the text.
Dithering
A technique of filling the gap between two pixels with another pixel having an average value of the two to minimise the differences or add detail to smooth the result
Doctor blade
In gravure, a knife-edge blade is pressed against the engraved printing cylinder, which wipes away the excess ink from the non-printing areas.
Dot
The individual element of a halftone.
Dot gain
In printing, a defect in which dots print larger than they should, causing darker tones or stronger colours.
Dots per inch (dpi)
A measure of the resolution of a screen image or printed page. Dots per inch (dpi) are a more appropriate term. In metric terms dots per centimetre, (cm). A dot per inch ruling will be 2.54 times the same dots per cm screen.
Draw-down
In ink making, a term used to describe ink chemists method of roughly determining colour shade. A small glob of ink is placed on paper and drawn down with the edge of a putty knife spatula to get a thin film of ink.
Drawing cartridge
An acid free paper made to accept watercolour painting.
Drier
In ink making, a substance added to hasten drying.
Drop-out
Potions of originals that do not reproduce especially coloured lines or background areas (often on purpose).
Dummy
A preliminary layout showing the position of illustrations and text, as they are to appear in the final reproduction. A set of blank pages made up in advance to show the size, shape, form and general style of a piece of printing.
Duotone
In photo-mechanics, a term for a two-colour halftone reproduction from a one-colour photograph.
Duplex paper
Paper with a different colour or finish on each side.
Duplicating film
A film for making positives from positives, and negatives from negatives. In colour reproduction, a special film used for making duplicates of colour transparencies.
Dynamic range
Density difference between highlights and shadows of scanned subjects.