Printing Terms Dictionary

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DARPA: See Defense Advanced Research Projects Agency.

Data: According to AT&T Bell Labs: Data is "A representation of facts, concepts or instructions in a formalized manner, suitable for communication, interpretation or processing."

Data Communications: The movement of data between points, including all the manual and machine operations necessary for this movement. Contrast with data transfer.

Data Content Model: SGML-speak for the occurence notation that describes what other markup is legal within the context of a specific markup element.

Data Compression: Reducing the amount of electronic "space" data takes up. Methods include replacing blank spaces with a character count, or replacing redundant data with shorter stand-in "codes". No matter how data is compressed, it must be decompressed before it can be used.

Data File: Any file created within an application: a word processing document, a spreadsheet, a database file, a chart, etc. Also known as a document.

Data Frame: The structured packets into which data is placed by the Data Link Layer.

Datagram: a packet of information and delivery data that is routed on a network.

Data Shift: In color process printing, it describes a shift in one of the channels of data that comprise the image file and could cause inconsistent color in some area of the image.

Data Transfer: The movement of data inside a computer system.

Database: Data that has been organized and structured in a disciplined fashion, so that access to information of interest is as quick as possible. Database management programs form the foundation for most document storage indexing systems.

DBMS: Database Management System. A complex system of programs and utilities used to define, maintain, and manage access to large collections of online data.

DCS: Desktop Color Separation. Developed by Quark. A DCS file is composed of five files. The main file is a composite with pointers to separation files and a low-resolution PICT preview file. There are four separations files, one for each process color.

DDCP: Direct Digital Color Proofing, a prepress proofing method which creates color proofs without the need for film or plates by using only digital data.

DDES: Digital Data Exchange Standards, a set of established formats, protocols, and values allowing one vendor's equipment to exchange data with another vendor's equipment. In color process printing, data can be exchanged between Color Electronic Prepress Systems.

Debug: The process of detecting, locating, and removing mistakes or malfunctions from newly developed software or hardware components of a computer.

Decompress: To reverse the procedure conducted by compression software, and thereby return compressed data to its original size and condition.

Decrement: In color process printing, it describes the decrease of a brightness, hue, or saturation value in an image.

Dedicated Device: A piece of hardware that is permanently assigned to one task. The task, however, can be changed by reprogramming or by the introduction of different software.

Dedicated System: Describes the permsnent assignment of an entire electronic system to one task.

Defense Advanced Research Projects Agency: An agency of the U.S. Department of Defense that sponsored the development of the protocols that became the TCP/IP suite. DARPA was previously known as ARPA, the Advanced Research Project Agency, when ARPANET was built.

Degausser: A device that removes unwanted magnetism from monitors or the heads in a tape or disk drive mechanism.

Delete: Describes the action of discarding data from memory or storage.

Delimiter: The "divider" character, often a comma, between separate fields in database records. It is a special character that indicates a record or field boundary within a text stream, rather than being interpreted as an actual part of the text itself.

Demilitarized Zone (DMZ): Computer slang used for a protected network that sits between the Internet and the corporate network.

Densitometer: In photography, a sensitive photoelectric instrument which measures the density of photographic images or of colors. In lithography, a reflection densitometer is used to measure the density of the ink colors to determine they are consistent throughout the run. A transmission densitometer can be used to check reproduction dot sizes in order to maintain quality assurance in color. Both measure optical density and are considerably more sensitive and accurate than is the human eye.

Density: A measure of the relative difference between a white area and a toned or black area. Can be applied both to black and white and color. Or the ability of a material to absorb light. It is inversely proportional to the amount of light reflected or transmitted through the sample.

Descenders: A typographic term for the portion of lowercase characters that falls below the main body of the letter. The lower case letters g, j, p, q and y have descenders.

Desktop: Slang for any computer function that can be done on a standalone PC, rather than a larger, more powerful, computer.

Desktop Publishing: The term applied to the creation of printed documents using a PC. The documents may be printed directly from the desktop publishing application software (usually with a desktop laser printer), or prepared for a commercial printing process. Do not confuse with "electronic publishing," which refers to electronically preparing documents which are to be read by electronic means.

Detail Contrast: In electronic scanning, the ability to increase the apparent detail contrast from light to dark and from dark to light by simple electronic manipulation. This produces an increased visual contrast on edge sharpness, thereby enhancing the image. The particular control section of a scanner that carries out this particular function is the unsharp masking area (USM).

Developing agent: The chemical in a photographic developer that converts exposed silver halide to visible black metallic silver.

Device: Any gadget that is plugged into a computer. May also be reffered to as an "external device." Examples are disk drives, video monitors, keyboards and printing devices.

Device Driver: A miniture program that acts like a translator, converting the output from one device into data that another device can understand. For example, a PC-compatible needs a device driver before it can understand the signals from a mouse; and a Macintosh needs a device driver in order to interact with a fax-modem.

Device Independent: A program or file format that can be used with two or more different computing devices and produce identical results. For example, a page saved in PostScript format should be printable on an HP LaserPrinter IV or on a Linotronic output. device.

Dialog Box: A rectangular box that either requests or provides information. Many dialog boxes present options to choose from before Windows can carry out a command. Some dialog boxes present warnings or explain why a command can't be completed. ˜

Differential Spacing: In typography, allowing letters to take up varying horizontal space in relation to their widths. For example, and "i" takes up less space than an upper-case "W". Opposite of fixed spacing, where each letter is assigned the same space, regardless of its shape or width.

Digital: The use of binary code to record information. "Information" can be text in a binary code like ASCII, or scanned images in a bit mapped form, or sound in a sampled digital form, or video. Recording information digitally has many advantages over its analog counter part, mainly ease in manipulation and accuracy in transmission.

Digital Camera: The newest generation of video cameras transform visual information (lightness and darkness) into pixels, then translate the pixel's level of light into a number (or, in the case of color, into three numbers _ one for the level of red, green and blue in the pixel). These digital images can then be manipulated pixel by pixel to create exciting new applications in video and film production. They can also be compressed, stored and transmitted in more or less the same manner as traditional digital data.

Digital File: A art file that resides on disk, usually in a native application format. See also CREF.

Digital Proof: A proofing system that does not include the use of film. Data is sent to a printer and imaged directly onto a paper-based material. There are several limitations of a digital proof: 1)they do not use the film that will be used to produce plates, and thus are open to interpretation of the output device, 2)few of these devices print in the same dot pattern as is utilized in the printing process, and 3)the ink utilized in these printers is not representative of the inks used in the printing process and can show a vast color range and density not attainable on a printing press.

Digitize: To convert an image or signal into binary code. visual images are digitized by scanning them and assigning a binary code to the resulting vector or raster graphics data. Sounds are digitized by recording frequent "samples" of the analog wave, and translating that data into binary code.

Dipthong: In typesetting, two vowels which are joined to form a single character, also known as digraph. A special form of ligature.

Direct Image Film: Film that maintains the same polarity _ positive for positive, negative for negative _ as the image which it is duplicating.

Disc: Same as optical disc. A digital storage medium. Optical discs are made of a metal alloy recording surface sandwiched between a rigid substrate and a plastic protective coating. Lasers record data in the metal alloy by either creating tiny pits (ablation technique) or by causing small bubbles to form in the "negative" area, thereby reflecting the laser away. Generally, and in this dictionary, disc with a "c" means optical disc. Disk with a "k" means magnetic hard or floppy disk.

Disk: Same as magnetic disk. A round, flat magnetic recording medium with one or more layers deposited on the surface which data can be recorded onto.

Disk Drive: A device containing motors, electronics and other gadgetry for storing (writing) and retrieving (reading) data on a disk. A hard disk drive is one which is generally not removable from the machine. A floppy disk drive accepts removable disk cartridges.

Disk Operating System: Often abbreviated as DOS, a kind of low-level program which has to be present in the computer's memory at all times while the computer is running, in addition to any other programs that are being used. The system (known as DOS in PC-compatibles or The Finder on a Macintosh) manages all disk operations.

Disk Pack: A grouping of magnetic disks, resembling a stack of phonograph records, offering large capacity information storage.

Disk Space: The amount of bytes on a disk available for recording or storing data.

Display PostScript: The PostScript command set that renders images directly to the screen.

Display Type: Used for headlines and advertising copy, it is larger than 14 points.

Dithering: Simulating gray tones by altering the size, arrangement or shape of background dots.

DLL: See Dynamic Link Library.

DNS: Domain Name Service. An Internet service that maps sybolic names to IP addresses by distributing queries among the available pool of DNS servers.

Domain: For DNS, a group of workstations and servers that share a single group name.

Dot: The individual element of a halftone. Its size (density) can be related to the density of the original used to produce the halftone dot. The size of the dot is indicated by the percentage of the area it occupies from zero to on hundred percent. It may be several shapes including round, square or elliptical.

Dot Etching: In lithography, the chemical etching of silver halide halftone emulsions to increase or reduce the amount of color to be produced. Dot etching negatives increases color; dot etching positives reduces color.

Dot Gain: An increase in the size of halftone dots that may occur as a result of errors or imperfections in any of the steps between screening an image and printing it onto paper. Common causes of mechanical dot gain are incorrect plate exposure, excessive tack or incorrect viscosity of printing ink, excessive ink film thickness, internal reflection of the ink, or too much preasure between the blanket roller and the impression cylinder.

Dot Pitch: The distance of one phosphor dot in a CRT to the nearest phosphor dot of the same color on the adjacent line.

Dot Spread: In printing, a defect in which dots print larger than they should, causing darker tones or colors. (See dot gain)

Double Burn: The merging of two films into one using a contact screen camera. It is usually used to bring the black text into the black separation.

Download: The transfer of data from a computer or telecommunications network to another electronic device or storage medium.

DPI: Dots Per Inch. A measurement of output device resolution and quality. Measures the number of dots a printer can print per inch both horizontally and vertically. A 600 dpi printer can print 360,000 (600 by 600) dots on one square inch of paper.

Dr. Web: A group of dedicated individuals who answer Web-related questions about the Web through a Web screen.

Drag: A function of the mouse by which an element on the screen of a monitor is moved with the cursor, while holding down the mouse button and moving the mouse.

Drop Capital: At the beginning of a paragraph, the initial capital letter can be modified to make a drop capital bydescending the letter below the baseline of the first line of text.

Drum: The common name for the photoconductive cylinders used on scanners and plotters.

Dry Processing: Method in which an exposed latent image is made visible without chemical treatment (usually a heat process.

Dry Silver Film: Thermal process film. A non-gelatin silver film type which is processed by heat, not chemicals.

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, color, form and general style of a piece of printing.

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

Duplicating Film: Special films made for color and black and white uses.

Dynamic Link Library (DLL): A file of functions, compiled, linked, and saved seperately from the processes that use them. Functions in DLLs can be used by more than one running process. The operating system maps the DLLs into the process's address space when the process is started up or while it is running. Dynamic link libraries are stored in files with the DLL file extension.

Dynamic Range: A scanner's ability to capture an image's gradations from the lightest highlight to the darkest shadow.