Gatefold
Two or more parallel folds on a sheet with the end flaps folding inward.

Generation
Each succeeding stage in reproduction from original copy.

Genuine watermark
Watermark made with a dandy roll.

Ghost halftone
A light halftone that may be overprinted with solid copy.

Ghosting
1) A faint image appearing in an area of a printed sheet where it was not intended is known as ghosting. Mechanical ghosting develops as a repeat image on the same side of a sheet due to on-press conditions, such as blanket problems or ink starvation. Chemical ghosting develops when an image is transferred onto the backside of a sheet from the front of the sheet below. This problem occurs during the ink drying process and is especially bothersome because it cannot be detected until the job has been completed. 2) A screening technique that entails scanning an image full-strength, and then screening it back to reduce the dot size.

Gloss ink
Ink containing an extra quantity of varnish, which gives a glossy appearance when dry.

Glued-on cover
A cover fastened to the text with glue.

Grade
A type or class of paper with the same composition and characteristics, which include brightness, opacity, cotton content, etc. Grade refers to general paper categories such as writing, text and cover, and specific company brands.

Grain
The direction in which most of the fibers lie on a finished sheet of paper. Paper folds more easily with the grain, it offers greater resistance to being torn across its grain and demonstrates greater tensile strength in the direction of the grain. Binding books parallel to the grain allows for a smoother fold than working across the grain. Grain direction of sheetfed papers is usually indicated by underlining the number, such as, 23" x 35". On a web press, the grain direction should run along the length of the paper web.

Grain direction
The direction of the fibers in paper.

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 length of the sheet.

Grain short
Opposite of grain long. Grain of the paper runs at the right angles to the longest dimension of the sheet. Fiber alignment in grain short paper parallels the sheet's shortest dimension.

Grainy printing
Printing characterized by unevenness, particularly of halftones.

Grammage
The basis weight of paper stated in metric terms of grams per square meter and expressed as g/m2. Thus a sheet of paper 17 x 22 with a basis weight of 20 lbs. for 500 sheets would be expressed metrically as 75 g/m2. To convert from basis weight to grams per square meter (g/m2), multiply basis weight by 1406.5 (a constant factor) and divide by the number of square inches in base sheet.

Gravure
An intaglio, or recessed, method of printing that uses recessed images etched onto a flat or cylindrical plate which moves through an ink pool. A blade scrapes excess ink off the plate, leaving ink only in the recessed areas. A second cylinder presses the paper against the plate so that it picks up ink from the wells. Gravure is ideally suited for multimillion copy runs because the presses can run at extremely high speeds and the intaglio plates are more durable.

Gray balance
The dot values or densities of cyan, magenta, and yellow that produce a neutral gray.

Gray scale
A strip of standard gray tones, ranging from white to black, placed at the side of original copy during photography to measure tonal range and contrast (gamma) obtained.

Grippers
A row of clips holding the sheet of paper in place as it speeds through the printing press.

Gripper edge
The leading edge of paper that moves through a printing press or folding machine. A 3/8" allowance in the paper must be made for the gripper edge.

Gripper margin
Unprintable back edge of a sheet of paper on which grippers bear, usually 1/2 inch or less.

Groundwood
Paper made from pulp created in one of several processes that use virtually the whole tree. Sometimes chemical and heating processes are used in the pulping process. Groundwood paper retains the lignin from the trees, which causes the paper to yellow and deteriorate relatively quickly.

Guide edge
The edge of a printed sheet at right angles to the gripper edge, which travels along a guide on the press or folder. This edge, like the gripper edge, should never be altered or mutilated between the printing and folding operations. It is the shorter edge of the sheet.

Guide marks
A method of using crossline marks on the offset press plate to indicate trim, centering of the sheet, centering of the plate, etc. Sometimes called register marks.

Guide side
The side the press uses to guide the sheet to the exact side toward the operator. Also known as operator or control side.

Guillotine
A French guillotine-style cutting machine that trims stacks of paper to size with a downward, chopping movement.

Gutter
The blank space or inner margin on a press sheet from the printing area to the binding.