Galley Proof 

A printout of text used for proofreading before final page assembly.

Text copy before it is put into a mechanical layout or desktop layout.

Gang 

Getting the most out of a printing press by using the maximum sheet size to print multiple images or jobs on the same sheet. A way to save money.

To halftone or separate more than one image in only one exposure. Also to print two or more finished products on the same sheet during one press run.

Ganging 

When a printer runs a variety of different jobs together for more efficient production.

Gapless Press 

A web press with special blanket cylinders that, with each rotation, allow more printing per square inch. This larger print space plus a shorter cutoff point can save a significant amount of paper on large runs.

Gather 

To assemble folded signatures in proper sequence.

Gear Streaks 

Parallel streaks appearing across the printed sheet at the same interval as the gear teeth on the cylinder.

Generation 

Stages of reproduction from original copy. A first generation reproduction yields the best quality.

Ghost bars 

A quality control method used to reduce ghosted image created by heat or chemical contamination.

Ghosting 

A faint printed image that appears on a printed sheet where it was not intended. More often than not this problem is a function of graphical design. It is hard to tell when or where ghosting will occur. Sometimes you can see the problem developing immediately after printing the sheet, other times the problem occurs while drying. However the problem occurs it is costly to fix, if it can be fixed. Occasionally it can be eliminated by changing the color sequence, the inks, the paper, changing to a press with a drier, printing the problem area in a separate pass through the press or changing the racking (reducing the number of sheets on the drying racks). Since it is a function of graphical design, the buyer pays for the increased cost.

Phenomenon on a faint image on a printed sheet where it was not intended to appear.

Gloss 

A shiny look reflecting light.

Goldenrod Paper 

Specially coated masking paper in yellow or orange used by strippers to assemble and position negatives for exposure on plates.

Gradation 

The relationship of the tonal values of an image to its intermediate films and reproduction as well as magnetic or optical representation. It may also refer to the tonal values within the picture.

Grain 

The direction in which most fibers are aligned.

Grammage 

The metric basis weight of paper. Weight is expressed in grams per square meter.

Gravure Printing 

A high-quality printing technique that uses direct contact between an etched copper plate and the paper. This technique is rather expensive because the plate has a relatively high cost. However, it is the best way to print high quality, large volume materials such as brochures and annual reports.

Gravure 

The process of printing from cylinders that contain cells that hold the ink for transfer to the substrate. In gravure color printing, each succeeding color is printed on a dry color, rather than one still wet as in letterpress and offset lithography.

Gray Balance 

The proper amount of cyan, magenta and yellow printing to produce a gray scale with no apparent dominant hue.

Gray Component Replacement (GCR) 

A color separation process that uses the black printer for the neutral gray portion of any color. Instead of mixing cyan, magenta and yellow to produce those grays, they are replaced with black ink. GCR deepens the shadows in an image that lacks depth. GCR completely replaces the grays with processblack, unlike UCR which reduces process colors in the neutral grays and addsblack.

Gray Stabilization 

Ability to maintain neutral gray balance during a color reproduction. The use of GCR helps to stabilize neutrals.

Grindoff 

The approximately 1/8 inch (3mm) that is removed along the spine of gathered signatures before perfect binding.

Gripper Edge 

The leading edge of a sheet which is held by the grippers.

Gripper Margin 

The unprintable area of the paper where it is gripped as it passes through a printing press. Usually measures a half inch or less.

Unprinted space allowed for the printing press to grip the sheet. This should be a minimum of 3/8 inch.

Grippers 

Metal fingers that clamp onto the paper and control its flow as it passes through the press.

Gutter 

The inside margin of a bound page.

The space between the printed area and the binding. Similar to margins.

Hairline Register 

Register within plus or minus one-half row of dots.

Hairline 

A very thin line or gap about the width of a hair or 1/100 inch.

Half tone 

A continuous-tone photograph reduced to tiny dots of various sizes, that when printed, give the illusion of continuous tones.

An image composed of tiny dots whose variations in size create the illusion of variations in tone. Traditionally, a halftone screen was used to convert a continuous tone image into a halftone; such screening is currently done electronically.

Converting a continuous tone to dots for printing.

Halftone-based digital proofing 

Producing a proof with reliable color and halftone pattern directly from a digital file, usually by electronic process, without producing a set of film negatives.

Hard Copy 

A printed paper copy of output in readable form. It is also a transparency film or photograph of an image displayed on the monitor.

The output of a computer printer, or typed text sent for typesetting.

Hard Dots 

Second generation dots or laser-generated dots that have hard edges without any fringe.

Hard Proof 

A color proof made on a substrate from production films or on a substrate directly from the stored pixel data. The latter is usually referred to as a digital hard proof, and a video proof as a digital soft proof.

Head 

The top of a page or book.

Heatset 

Web printing process whereby non-absorbent paper goes through the press and the ink is dried by heat.

Hickey 

Reoccurring unplanned spots that appear in the printed image from dust, lint, dried ink.

Spot on a printed sheet usually due to dust, lint or bits of paper.

High-bulk paper 

A paper made thicker than its standard basis weight.

Highlight 

The lightest area of a photograph that has the smallest or fewest dots when made into a halftone.

The lightest areas in a picture or halftone.

HLS/HSV 

Abbreviations for hue, lightness and saturation and hue saturation and value. These are different names for the same color-control options found in most desktop software.

Holdout 

A property of coated paper with low ink absorption which allows ink to set on the surface with high gloss. Too much holdout can cause ink to rub off or mark the next sheet.

Hot Spot 

Printing defect caused when a piece of dirt or an air bubble caused incomplete drawdown during contact platemaking, leaving an area of weak ink coverage or visible dot gain.

House Sheet 

Paper kept in stock by a printer and suitable for a wide variety of printing jobs.

Hue 

The attribute of color that designates its dominant wave length and distinguishes it from other colors.

Image area 

Portion of paper on which ink can appear.

Image to Plate on Press 

Technology that images one or more plates in position on press for color reproduction.

Image 

The digitized representation of a graphic element (photograph, painting, film) bitmapped in computer memory for display on a video monitor for output in paper or film form.

Imagesetter 

A high-resolution laser output device that writes data on photosensitive paper or film. The data is processed by a RIP and can record halftones and line images as well as type.

Imposition 

Laying out pages in a press form so that when the pages are printed and folded they will be in proper order.

Impression 

One sheet passing once through the press.

Putting an image on paper.

Impressions 

The total number of printed pages produced by the printer.

Imprint 

Adding copy to a previously printed page.

Imprinting 

To print new copy on a previously printed sheet, such as imprinting an employee's name on business cards.

In-line 

Components of a system arranged in a logical production sequence and in such a way that materials are automatically fed to the next component. An example would be a coating tower on a press to apply the lacquer or UV coating on the same pass as the color.

Indicia 

Postal information place on a printed product.

Indirect Screen 

The process of first separating a photo or artwork into the four process colors by creating continuous tones. The dots are then added using an additional process.

Ink Balance 

Relationship of the densities and dot gain of process inks to each other and to a standard density of neutral gray.

Ink fountain 

The reservoir on a printing press that hold the ink.

Ink Jet 

A method of printing images using jets that squirt minuscule drops of ink onto a variety of surfaces.

Inplant 

A department or division of a company that does printing only for that company.

Insert 

A printed piece designed to be placed into an already printed magazine or newspaper.

Intaglio 

Method of printing in which the image is etched below the non-printing surface. Gravure and engraving are the most common forms.

Intensity 

The measurement of color from dull to brilliant.

ISO 

International Standards Organization.

Job Ticket 

Form used by service bureaus, separators and printers to specify the production schedule of a job and the materials needed.

Jog 

To align the edges of a pile of paper by hitting or shaking against a flat surface.

JPG or JPEG 

A type of compression format for photographs that use full color, although some detail can be lost in the process. Short for Joint Photographics Experts Group.

K 

Abbreviation for black in four-color process printing.

Kelvin 

A unit of measure used to describe the color temperature of a light source, such as the 5000K standard viewing conditions.

Key Plate 

Negative or plate that prints the most detail (usuallyblack) and to which other plates are aligned.

Keyline 

A guide to a printing job. All the key elements such as type or illustrations are pasted down (usually with wax) to indicate size and position on artwork board or poster board.

Keylines 

Lines on mechanical art that show position of photographs or illustrations.

Kilobyte 

K, Kb or KB. A unit of measuring digital information which equals 1024 bytes.

Kiss Cut 

To die cut the top layer but not the backing of self-adhesive paper.

Kiss die cut 

To cut the top layer of a pressure sensitive sheet and not the backing.

Kiss Impression 

Lightest possible impression that will transfer ink to a substrate.

Knock Out 

To clear an area of absolutely every printing dot; or to outline an image and drop out all dots surrounding it.

To mask out an image.

Kraft Paper 

Strong brown paper made with unbleached wood pulp and used for grocery bags, envelopes and wrapping paper.

Press Definitions L - O

Lacquer -- Overrun

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