The Wells & Drew Printing Dictionary – G
G
gain, dot:
- can be caused by the ink consistency being poorly controlled; the ink too soft. Also can be caused when the plate was either overexposed for negative working plates or underexposed for positive working plates.
- galley proof:
- a proof of text copy before it is formatted 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 printing:
- grouping related jobs using same paper and inks. Grouping more than one job on a single plate.
- 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.
- gate fold:
- a sheet that folds where both sides fold toward the gutter in overlapping layers.
- gathered
- : signatures assembled next to each other in the proper sequence for binding, as compared to nested. Also called stacked.
- genuine watermark:
- watermark made on the paper machine, with a dandy roll.
- ghosting:
- ghost images are unwanted images that reduce print value.
- ghosting, chemicals
- : occurs when a drying ink film affects the drying of previously printed ink film. To correct, allow at least 24 hours for first printed side to dry before backing up. 2) Can occur with slow drying inks. To correct, add a drier ink to decrease drying time, consult with your ink manufacturer or supplier about faster drying inks.
- ghosting, mechanical:
- occurs when ink form rollers cannot supply enough ink coverage on the forms. Also occur when there is too much water run on the plate.
- gilding:
- originally done with actual 14kt. gold leaf.A process used to finished the edges of books,business cards, announcements other fine stationery products.The process yields metallic edges to the piece being gilded.
- glassine, patched window:
- the most opaque patching material.
- glazed:
- paper with a glossy surface, applied either during manufacture or subsequently. Various means of obtaining the patent leather-like surface.
- gloss:
- gloss results from the specular reflection of light and occurs when specular reflection exceeds the diffuse reflection from various viewing angles. Paper gloss can be measured at various angles of illumination.
- grade:
- a type of paper or pulp which is distinguised from other papers or pulps on the basis of its characteristics such as its raw material content, manufacturing history, appearance and/or end use.
- gradation:
- in photographic originals and lithographic reproductions, the range of tones from the brightest highlights to the deepest shadows.
- grain:
- direction in which most of the fibers lie in a finished sheet of paper. Fibers flow parallel to the direction in which the paper travels on the paper machine during manufacture.
- grain direction:
- fundamental property of paper resulting from the alignment of fibers flowing onto the paper machine.
- grain long
- : term used to designate that the grain of the paper is parallel to the longest measurement of a sheet of paper. The fibers are aligned parallel to the longest measurement fo a sheet of paper. The fibers are aligned parallel to the length of the sheet.
- grain short:
- perpendicular to grain long. Grain of the paper runs at right angles to the longest dimension of the sheet. Fiber alignment in grain short paper parallels the sheet’s shortest dimension.
- grain, straight:
- envelopes manufactured with the grain direction parallel to or perpendicular to the length or width of the envelope.
- graining:
rougening the smooth surface of rolled metal plates enabling them to better retain water. Plates are regrained to remove all traces of previous images to produce a fresh grain.
graphic arts:
- the crafts, industries and professions related to designing and printing on paper and other substrates
- graphic arts film:
- film whose emulsion yields high contrast images suitable for reproduction by a printing press, as compared to continuous-tone film. Also called litho film and repro film.
- graphic design:
- arrangement of type and visual elements along with specifications for paper, ink colors and printing processes that, when combined, convey a visual message.GraphicsVisual elements that supplement type to make printed messages more clear or interesting.
- gravure:
- printing process which employees recessed ink-holding image which comes directly in contact with paper.
- gray balance:
- printed cyan, magenta and yellow halftone dots that accurately, reproduce a neutral gray image.
- gray component replacement:
- technique of replacing gray tones in the yellow, cyan and magenta films, made while color separating, with black ink. Abbreviated GCR. Also called achromatic color removal.Abbreviation GCR
- gray levels:
- number of distinct gray tones that can be reproduced by a computer.Gray ScaleStrip of gray values ranging from white to black. Used by process camera and scanner operators to calibrate exposure times for film and plates. Also called step wedge.
- grind edge:
- alternate term for binding edge when referring to perfect bound products.
- grindoff:
- approximately 1/8 inch (3 mm) along the spine that is ground off gathered signatures before perfect binding.
- gripper edge:
- leading edge of a sheet of paper as it passes through the printing press.
- 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.
- groundwood papers:
- papers containing more than 10% mechanical groundwood or thermomechanical groundwood pulp.
- GSM:
- the unit of measurement for paper weight (grams per square meter).
- guillotine:
- device that is used to cut or trim stacks of paper to the desired size, similar to the French guillotine. Three types exist, manually operated, electrically powered cutters and automatic spacing cutters.
- gum, back:
- the adhesive used as a permanent seal between the bottom and side envelope flaps
- gum, full:
- continuous layer of adhesive applied on the seal flap.
- gum, live stamp:
- there is no top flap gum directly under the position where the postal stamp is placed to avoid blocking.When postage stamps are applied prior to filling an envelope, the moisture from the stamp can inadvertently moisten the envelope flap and cause the envelope to be sealed. Gum for live stamp process avoids this.
- gum, seal:
- emoistenable adhesive applied to the top flap of the envelope
- gum, split:
- a layer of adhesive that is non-continuous and normally broken at the two points where the flap comes in contact with the side and back seam to avoid blocking.
- gutter:
- the blank space or inner margin on a press sheet from printing area to binding.