Gain: The increase in signaling power as an audio signal is boosted by an electronic device. It's measured in decibels (dB).
Galley Proof: A proof of text copy before it is formated for the page.
Gamma: A measure of contrast in photographic images. A densimetric evaluation of graph paper indicating highlight to shadow contrast in terms of density values, plotted on a graph to establish the maximum and the minimum, the difference between them being the gamma.
Gamut: Every color combination that is possible to produce with a given set of colorants on a given device or system.
Gang Separations: A group of originals containing slides or prints of the same type, emulsion, highlight, middletone and shadow characteristics which will all be separated together as one piece. Highlights, middletones and shadows are set up for the average, Originals falling above or below the average will be lighter or darker than the average. There are no special tone, or color corrections done to individual pieces, because the separation is based on average readings found in the average of all the originals. Request for corrections from gang separations will result in additional charges.
Garbled: Corrupted data.
Gateway: A connection, in the form of a cable, device or computer, between two computers or systems that are dissimilar.
Generation: Each succeeding stage in the reproduction from the original copy.
GIF: Graphics Interchange Format. A compressed graphics file format patented by Unisys, and widely used in the online environment.
Giga: Meaning billion or thousand million. In computers, it is actually 1,024 times mega and is actually 1,073,741,824. One thousand gigas is a tera. No one knows what a thousand teras is ... yet.
GIGO: Garbage In, Garbage Out. If the input data is wrong or inaccurate, the output data will be inaccurate or wrong. GIGO is often the problem with data entered by hand into computer systems.
GPIB: General Purpose Interface Bus, an interface bus developed by Hewlett Packard that became the standard interface bus recognized by the Institute of Electrical and Electronic Engineers (IEEE).
Gradation: In photographic originals and lithographic reproductions, the range of tones from the brightest highlights to the deepest shadows.
Grain: In photography, the grain is the granular particles in photographic emulsion of an original print or negative. The printing process causes the grain to become more apparent than in the original.
Graphics: For the purposes of this glossary, graphics are one of the three types of data that can be created, stored retrieved and manipulated (the other two are text and documents). Graphics are basically pictures and drawings, either created by computer or entered into the computer by scanning or photographing. See vector graphics, raster graphics and bit map for more.
Graphic Resolution: The level of quality of which graphics are printed. The higher the resolution, the better the quality of the printed graphics.
Gray Balance: In four-color process printing, proper proportions of the three-process colors (yellow, magenta and cyan) create the appearance of neutral gray with no apparent hue.
Gray Component Replacement (GCR): A technique for removing some or all of the cyan, magenta and yellow from color separations. If properly executed, the reproduction will appear the same or better than one that used conventional color reproduction without GCR.
Gray scale: The spectrum, or range, of shades of black an image has. Scanners' and terminals' gray scales are determined by the number of gray shades, or steps, they can recognize and reproduce. A scanner that can only see a gray scale of 16 will not produce as accurate an image as one that distinguishes a gray scale of 256.
Gray Value: The number (usually between 0 and 256) that specifies a particular shade of gray.
Gripper Margin: The unprintable blank edge on which the paper is gripped as it passes through a printing press. Usually measures a half inch or less.
GUI: Graphical User Interface. Pronounced gooey. A generic name for any computer interface that uses graphics, windows, or a pointing device instead of a purely character-mode interface. GUI were first developed by Xerox at Xerox PARC in Palo Alto, California, and first put into use with the MacOS.
Gutter: The two inner margins of facing pages of a publication.