SMART DIGITAL

Glossary A   B  C
The terms in this glossary were taken from a glossary published by CAP Ventures and they relate specifically to print on demand. For an in-depth discussion of computer-related terms, two texts are recommended: “Jargon: An Informal Dictionary of Computer Terms” (Robin Williams, Peachpit Press, 1993), and “The Computer Glossary:The Complete Illustrated Desk Reference,” 6th Ed, (Alan Freedman, AMACOM, 1993.)



A

8-bit
Tonal resolution (i.e., bit depth) for grayscale or color images that allows 256 shades of color or gray. The 256 shades are represented mathematically by taking two bits to the eighth power, 28.

24-bit
Tonal resolution (i.e., bit depth) for color images consisting of three 8-bit components, one for red, green, and blue. Each 8-bit portion allows 256 shades of color. Together the three components produce more than 16 million colors.

32-bit
Tonal resolution (i.e., bit depth) for color images consisting of four 8-bit components. The fourth component is usually used for creating transparency effects, masks, or process colors.

additive colors
The colors red, green, and blue (see RGB) are called the additive primaries because when mixed together, they produce white light. See subtractive colors.

advanced function presentation (AFP)
An IBM Printing Systems architecture that is used to not only as a page description language, but also to track and troubleshoot documents as they progress from a database to a printed sheet to an envelope and ultimate mailing. At one time, AFP was known as advanced function printing, but the term “presentation” replaced “printing” because of the broad range of functions beyond printing that AFP provides. Components of AFP include AFPDS (AFP data stream), IPDS (intelligent printer data stream), and PSF (print services facility).

analog
A process that is continuous in nature, like the movement of the hands on a watch. Within print on demand, the term may be used to describe the difference between analog photocopiers (which use lenses and reflected light to copy a document) and digital copiers (which actually scan the document).

analog copier
A photocopier which uses lenses and reflected light to copy a document (as opposed to a digital copier which actually scans the document).





B

basis weight
The weight of 500 sheets of paper cut to a standard specific size. A basic sheet size is common to each major paper grade. The basic sheet size of cut-sheet paper is 17" x 22". If the total weight of 500 sheets of 17" x 22" paper is 20 lbs., the paper is described as 20-lb. paper.

bit
Bit is a contraction of the words “binary digit”. It is the smallest unit of information in a digital computer and can define two conditions (on or off, 0 or 1, black or white, etc.).

bit depth
A measure of the tonal resolution of a scanner or output device. For a scan, bit depth refers to the number of grays or color that are represented within each pixel. A one-bit scan can represent two levels: black and white. An eight-bit monochrome scan can represent 256 levels: black, white, and 254 levels of gray. A 24-bit color scan can represent over 16 million levels. For an output device, bit depth refers to the ability to vary either the size or the intensity of the smallest mark that they make.

bitmap
Strictly speaking, a bitmap is a resolution-dependent computer file (usually a scan, but perhaps a file from a paint program) in which each pixel contains one bit of tonal information. In practice, people don’t limit the use of the term bitmap to single bit per pixel images. See raster.

bits per second (bps)
The rate of data transmission by a modem, for example: 300, 1200, 4800, 9600, 14400, and 28800 bits per second (bps). Bits per second is sometimes referred to as “baud,” but bits per second is the more accurate term to describe modem speed.

blanket cylinder
In offset printing, the blanket cylinder is an intermediate cylinder which sits between the plate cylinder and the impression cylinder. The ink is transferred from the plate cylinder to the blanket cylinder, and then applied to the paper. This type of “offset” is used not only in offset lithography, but is also emerging in electro photographic devices.

bleed
The ability of a device to print text or images to the edge of the page. “No bleeds” means that you must maintain a margin on all four sides. A “full bleed” means text and images “bleed” off the page on all four sides. When a job is printed with a full bleed, it must be printed on a larger sheet and trimmed to size.

brightness
A standardized measurement of the percentage of light reflected back from a sheet. A 90 brightness indicates the sheet reflects 90% of the light striking it.

buffer
A high-speed area of storage temporarily reserved for use in performing the input/output operation from which data is read or into which data is written. One example is the Barco PageStreamer which provides a page buffer that stores pre-RIPped pages. It allows variable imaging or electronic collation. Without it, the RIP would not be able to keep up with the speed of the print engine.

burster-trimmer-stacker (BTS)
A post-processing device on fanfold printers which bursts (i.e., tears the pages into separate sheets), trims (i.e., tears along the perforated edge), and stacks the resulting sheets.

byte
A standard unit measure of computer file size. There are eight bits in a
byte. See gigabyte (GB), kilobyte (KB), megabyte (MB), terabyte (TB) and petrabyte (PB).





C

C1S, C2S
Paper terms referring to coated paper: coated on a single side (C1S), and coated on both sides (C2S).

CAD
Computer Aided Design

CAM
Computer Aided Manufacturing

caliper
Thickness of a single sheet of paper, in thousandths of an inch, as measured with a micrometer.

carrier
See developer.

central processing unit (CPU)
Central Processing Unit of a computer. Working alone or with other CPUs, it consists of a control unit and an arithmetic-logic unit (ALU).

charge
An intrinsic property of electricity. A charge is either positive or negative. Charges are used to create latent images in electrophotography.

click charge
A per-page maintenance fee incorporated into service contracts by vendors of mid-range and production-oriented printers or copiers. Click charges normally are charged in addition to a flat monthly maintenance rate. Click charges are not used by vendors of offset lithographic equipment, and only a few vendors use them for production-oriented digital color printers.

client-server architecture
A system in which databases reside on a server (i.e., a networked microprocessor-based host) that handles the bulk of the processing. The client (i.e. a desktop computer) provides the user interface but does little of the processing.

CMYK
Abbreviation for cyan, magenta, yellow, and black. Cyan, magenta, and yellow are the primary colors used in printing that together can reproduce a wide range of colors. Black is added to CMY to reinforce details and provide neutral blacks and grays. Black is abbreviated K to keep from confusing it with B for blue. See RGB.

coated paper
Coated papers contain a layer of clay or pigment, in combination with an adhesive, that is applied to the surface of the paper.

color server
A device which allows a digital color copier to operate as a network printer.

compact disk-read only memory (CD-ROM)
A computer storage mechanism that can hold up to 600 megabytes (MB) of data. CD-ROMs look just like music CDs and are used for holding massive files like catalogs, digital libraries, or encyclopedias. They provide an outlet beyond print for electronic files. CD-ROMs are “read only”, meaning you cannot copy a file onto a CD-ROM. CD-ROMs are somewhat limited by their slow access time relative to other computer storage methods.

compact disk-rewritable (CD-RW)
CD technology that can be re-written.

conductivity
Defines the electrical properties of a sheet of paper. Conductivity influences toner transfer and image quality of many print-on-demand systems.

continuous form
A type of printer paper that is often used for forms or in database environments. Holes punched along the edge allow the printer to advance the paper. It is perforated between sheets, and also along the edge. It is also called fanfold.

contone
A contraction of the words “continuous tone”. A contone is an image which contains a continuous range of shades of colors. An example of a contone is a photograph or a watercolor painting.

controller
One or more microprocessors that direct the operations of a printer, disk drive, or multiple terminals.

corona
In an electrophotographic system, the corona cleans the photoconductive drum or belt of the image after it has printed.

cover paper
Heavier papers generally used for book covers, folders, greeting cards, business cards, brochures or anything that requires stiffness.

CPM
Copies per minute.

cut size
Business or writing papers cut to a finished size of 8.5" x 11", 8.5" x 14", or 11" x 17".