DAM (Data Asset Management) A virtual warehouse for archiving digital content in a centralized location.

Dampening system The mechanism for transferring dampening solution to the plate during lithographic printing.

Data aggregation When data is gathered, summarized, and refined. After it is gathered, the refined statistical data is often reported directly back to the requestor.

DCS (Desktop Color Separation) In digital prepress, a data file defined to assist in printing process color separations using desktop color systems. Using DCS, five files are created: cyan, magenta, yellow, and black image data, and a composite color preview of the color image.

Deckle In papermaking, the width of the wet sheet as it comes off the wire of a paper machine.

Deckle edge The untrimmed feathery edges of paper formed where the pulp flows against the deckle frame.

Densitometer A photoelectric instrument that measures the density of photographic images, or of colors. In printing, a reflection densitometer is used to measure and control the density of color inks on the substrate. Densitometry may be built into reproduction devices.

Density The degree of darkness (light absorption or opacity) of a photographic image.

Descender That part of a lowercase letter that extends below the main body, as in "p."

Desktop publishing The process of designing and composing pages using a combination of standard computer, off-the-shelf software, device-independent page description language such as PostScript, and then outputting final pages on a printer, imagesetter, platesetter, or digital printer.

Device-independent The characteristic of a computer program or system that allows different output devices to image the same file more or less the same.

Diecutting The process of using sharp steel rules to cut special shapes for labels, boxes, and containers from printed sheets. Diecutting can be done on either flatbed or rotary presses, or specialized equipment. Rotary diecutting may be done inline on the printing press.

Die-stamping An intaglio process for the production of letterheads, business cards, etc., printing from lettering or other designs engraved into copper or steel.

Diffusion transfer In photography and platemaking, a system consisting of a photographic emulsion on which a negative is produced and a receiver sheet on which a positive of the image is transferred during processing.

Digital Asset Management (DAM) Also known as Media Asset Management, it is a segment of the content management market focused on the systematic cataloging and management of digital media (text, images, video, and audio), and some physical media to enable their efficient storage, retrieval, and reuse.

Digital color proof A color proof produced from digital data without the need for separation films.

Digital inks See toners.

Digital photography Uses a light-sensitive sensor in place of film to capture images electronically. Digital photography is used widely by photojournalists and is being applied increasingly by both professional photographers and consumers.

Digital plates Printing plates imaged using lasers or other high-energy sources driven by digital data in a platesetter.

Digital printing Printing by plateless imaging systems that are imaged by digital data from prepress systems. Includes toner, ink-jet, and other processes. As Steve Suffoletto of RIT said in our Print Buyer Boot Camp session, "digital printing is any process that can regenerate a new image for each impression or print cycle." The key words are "new image for each impression." Traditional offset presses don't do digital - they print static impressions over and over again.

Digitizer A computer peripheral device that converts an analog 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.

Display type Type set larger than the text, as in headings.

Distribute and print Where the job is sent to printers around the country, printed locally, and mailed less expensively.

Dithering A technique for alternating the values of adjacent dots or pixels to create the effect of intermediate values. Dithering refers to the technique of making different colors for adjacent dots or pixels to give the illusion of a third color. Dithering is a substitute for halftone or contone reproduction.

DMZ (Demilitarized Zone) A computer or subnetwork that resudes between a trusted internal network, like a LAN, and an external network, such as the Internet.

Doctor blade In gravure, a knife-edge blade pressed against the engraved printing cylinder that wipes away the excess ink from the non-printing areas.

DOS (Disk Operating System) An operating system (set of programs) that instructs a disk-based computing system to manage resources and operate peripheral equipment.

Dot Smallest digital imaging or screening element. Common usage does not clearly differentiate between dots and spots. A halftone dot is composed of many spots. The fineness of a halftone screen is measured in "lines per inch" or lpi. In AM screening the dots vary in size; in FM screening all the dots are the same size. Dots per inch (dpi) is a measure of image quality.

Dot gain A defect in which dots print larger than they should, causing darker tones or stronger colors. There are two kinds of dot gain: mechanical and optical. When the plate is exposed, light scatters a bit and can cause 3-5% optical dot gain. Then during the printing process, the paper and the printing process can cause the ink to spread, thus creating mechanical dot gain at a theoretical 50% dot. Dot gain means the difference between a dark print and an acceptable print.

Dots per inch (DPI) A measure of the resolution of a screen image or printed page.

Download Sending information to another computer or to an output device. The term "upload" is used synonymously.

Draw-down A term that is used to describe an ink chemist's method of roughly determining color shade. A small glob of ink is placed on paper and drawn down with the edge of a putty knife or spatula to get a thin film of ink.

Drop-out Portions of originals that do not reproduce, especially colored lines or background areas (often intentionally). White type on a colored background is often called a drop-out.

Dryer A substance added to ink to hasten drying.

DTP Acronym for desktop publishing.

Dummy A preliminary layout showing the position of illustrations and text as they may appear in the final reproduction. A set of blank pages made up in advance to show the size, shape, form, and style of a piece of printing. A dummy presents the look and feel of a printed product prior to production.

Duotone A term for a two-color halftone reproduction from a one-color photograph.

Duplex+ "Prints duplex" means it's printed on both sides of the sheet. "Perfecting" means the same thing. A perfecting press prints both sides of the sheet at the same time.

Duplex paper Paper with a different color or finish on each side.

DVD (Digital Video or Versatile Disk) A disk that can store audio, video, and computer data at 4.7 or more gigabytes per disk.

Dynamic range Density difference between highlights and shadows of scanned subjects.

Dynamic web effect The ability of a web page to change appearance as a result of a visitor’s action.