SMART DIGITAL

Glossary   Q   R   S 



R

random access memory (RAM)
Short-term computer memory that is used to store information that a computer is processing at any given moment. RAM is a key factor in RIP implementations, particularly for color servers.

raster
A raster is a resolution-dependent computer file (usually a scan, but perhaps a file from a paint program). The term is sometimes used synonymously with bitmap, although raster really has a broader meaning. A raster is an electronic file which describes points mathematically on a grid. The finer the grid, the higher the spatial resolution (and the larger the file size). A raster could describe files of varying tonal resolution (i.e., bit depth). Raster files stand in contrast to vector files which use mathematical formulas to describe lines, curves, and tints.

raster graphics
A process in which graphics are formed by an array of pixels arranged in rows and columns.

raster image processor (RIP)
A device that translates the instructions for the printing of a page into the actual pattern of dots (i.e., a raster) needed by the printer in order to image the page.

recycled paper
Currently, most observers define recycled paper based on Executive Order 12873 by the Clinton administration which states that papers purchased by the Federal Government must include at least 30% post-consumer content for uncoated and 10% post-consumer content for coated papers.

redundant array of inexpensive disks (RAID)
A cluster of computer disks for the storage of data, RAID provides good throughput rates and also provides backup in case a single disk fails.

re-imageable systems
Systems that produce pages or images that vary from one impression to the next. This gives them great flexibility for personalization or electronic collation. Fixed-image plate systems can only reproduce the same image over and over again until the plate is changed.

re-purpose
The process of re-using data for a variety of purposes. For example, an electronic document could be printed, saved on a CD-ROM, or used for distribution on the Internet.

resolution
See spatial resolution and tonal resolution.

resolution (print)
The resolution of a laser and other printers is measured in dots per inch (dpi), and usually serves as a print quality parameter; resolution refers to the absolute or relative density of pixels on a CRT screen or dots on a page.

rewinder
A post-processing device used to re-wind a printed web of paper.

RGB
Abbreviation for red, green, and blue, the primary colors in the additive color model. The RGB model is used in color televisions, color scanners, color monitors, and color film recorders. See CMYK.

RIP
See Raster Image Processor.

RIT
Rochester Institute of Technology.

roll feeder
A device designed to feed roll paper into a printer, usually a high-speed, non-impact printer. The advantage of a roll feeder is that printing can occur for several hours without paper replenishment, while a traditional box of fanfold paper might last only a few minutes.





S

serial printer
A print device that prints one character at a time through a printhead moving across the line.

server
A shared device on a network that any user can access. The server can provide a variety of network services including electronic filing, mailing, printing, and communicating.

sheets per hour (sph)
A measure of the speed of a cut-sheet printer, most often used to describe an offset lithographic press.

short-run printing
A limited number of impressions (usually fewer than 5,000 but sometimes as many as 20,000) for a single job. This could mean 5,000 copies of a single sheet printed on one side, or, 200 copies of a 25-page document.

signature
A printed sheet containing numerous pages that is folded and trimmed to make a booklet. Multiple signatures may be placed side by side and bound as a book, or, they may be inserted one into another for binding.

simplex
Ability to print on one side.

sizing
A substance added to pulp before papermaking or to the surface of a finished sheet. Sizing serves several different functions, depending on the end use of the sheet: as a glue to hold fibers together, an enhancer of water resistant qualities, or as a controller of the reaction of ink with the sheet.

smoothness
A precise measurement of the surface texture of a sheet of paper. Smoothness plays an important role in how well a given paper will print on a given technology. A very smooth sheet may be too slippery for a system to move reliably. Too rough a sheet may affect image quality.

soft copy (or soft proof)
A document or image held in electronic memory and displayed on a computer screen. See hard copy. Soft proofing (i.e., the viewing of documents for customer approval) poses potential color and font consistency problems for viewers who may be using a variety of different kinds of monitors under many different viewing conditions at various locations.

spatial resolution (output device)
The number of marks that an output device (i.e., printer, imagesetter, platesetter, digital copier, digital press, etc.) can make in a given distance, usually an inch. Spatial resolution is generally expressed in dots per inch (dpi). See tonal resolution.

spatial resolution (scanner)
The number of marks that a scanner can read in a given distance, usually an inch. Resolution is usually measured in dots per inch (dpi) or pixels per inch (ppi). Input resolution may be true (i.e., unmanipulated) or interpolated (i.e., increased via post-processing). See tonal resolution.

substrate
The material onto which a pigment, toner, or ink is applied. Substrates include paper, films, vinyls, labels and plastic.

subtractive colors
Magenta, yellow, and cyan are the subtractive color primaries because they subtract light reflecting off of them. For example, only a portion of the white light that hits a patch of magenta ink will reflect to the viewer’s eye. The white light is made up of a red, a green, and a blue component. The ink absorbs the green component and reflects red and blue which is seen by the eye as magenta. See additive colors.