Printing Definitions

Accordion Fold
Zigzag type of fold in a sheet of paper where two or more parallel folds open in the manner of an accordion, permitting the paper to be extended to its full breadth with a single pull. Also called a fan fold.

Barrel Fold
Fold style of horizontal or vertical parallel lines representing a code that can be optically read and interpreted by a bar code scanner.

Bitmap
Computer image comprised of pixels.

Blanket
Rubber-coated pad mounted on a cylinder of an offset press that receives the inked image from the plate and transfers it to the paper surface.

Bleed
A printed area that extends beyond the trimmed edge of a printed piece. Bleed areas generally range from 1/8” to 1/4” (3.175 mm to 6.35 mm).

Butt
To join two elements edge to edge.

Camera Ready
Term describing an image or layout that is ready for print reproduction.

Chipboard
Solid cardboard used in packaging and for industrial purposes.

Choke
Slightly reducing an image to create a trap.

CMYK
Stands for cyan, magenta, yellow, and key (black). The primary ink colors that are combined on press or as printed digital output to produce a full range of colors.

Coated Paper
Paper with a smooth and sometimes glossy finish created by applying a clay coating to the surface.

Color Bars
Strip of colors printed on the edge of four-color process proofs and press sheets to check registration of all colors and to evaluate ink density

Cover Stock
Fine printing paper with a basis weight or grammage paper that is heavier than text or book weight papers.

Creep
Where the middle pages of a folded signature extend slightly beyond the outside pages. Also called push out or thrust.

Crop
Trimming part of a photograph or illustration so that undesirable or unnecessary elements are eliminated.

Crop Marks
Marks placed on the edges of a mechanical to indicate where a printed piece should be trimmed. Also called trim marks.

Crossovers
Where a printed area that appears on two-page spread rosses over the gutter. Also called gutter bleed.

Deboss
To produce a recessed impression on the surface of a paper by pressing it between two dies.

Density
The thickness of a layer of ink.

Die
Sharp metal rules mounted on a board for making die cuts, or a solid metal block used for stamping foil or an impression onto paper.

Die-cut
A decorative or unusual cut made in paper with a metal die

Direct Mail
Form of advertising that uses person-to-person communication by contacting individuals through the postal system.

Dot Gain
When halftone dots print larger on paper than they are on films or plates, they reduce detail and lower contrast. Uncoated papers tend to cause more dot gain than coated papers. Also called dot spread or press gain.

DPI
Used to measure the resolution of a scanned image. Higher dpi producers higher resolution and more detail.

Duotone
Halftone made of two colors.

Emboss
To produce a raised impression on the surface of paper by pressing it between two dies.

Engraving
Printing method using a metal plate with an image cut into its surface.

EPS
Computer file format used for placing images or graphics in documents.

FIM
A machine-detectable series of vertical bars printed in the upper corner of a business reply card or envelope that allows the US Postal System to automatically cancel letter mail.

Finish
Surface characteristics of paper. Examples of finishes include laid, linen, and vellum.

Flood
To print a sheet completely with an ink or vanish

Foil Stamp
Where foil and a heated die is stamped onto appear to form a printed impression.

Four Color Process
Method of printing that uses cyan, magenta, yellow, and black to reproduce full-color images. (See CMYK)

FPO
Stands for “For Position Only.” FPOs are stand-in replicas of imagery that will be printed. They are typically low-resolution (low-res) versions of high-resolution (high-res) images that are temporarily placed in a digital document to show how an image job is printed, the low-res images are replaced with their high-res counterparts.

Ganging
A coast saving technique where a number of different items are reproduced at the same time, as in ganging several items on the same sheet of paper or separating several items at the same percentage.

Gate Fold
A folding style where the outer edges fold inward to meet in the gutter, and then folded again at the point where they meet to form eight panels or pages.

GIF
An 8-bit, low-memory option for posting images online.

Grippers
The press mechanism that draws the paper through the cylinders of the press.

Gutter
The white space between columns of type or between pages on a two-page spread.

Halftone
Reproducing a continuous tone image by photographing it through a fine screen to convert the image into a series of dots.

Halftone Dot
Units in a halftone that, by their various sizes, re0create a continuous tone image.

Hickey
A spot or imperfection on a printed piece that occurs during the print run because of a speck of dust or other particle on the press interfered with the ink’s application on paper.

Imposition
An arrangement of pages on a printed sheet that enables them to be in the correct order when the sheet is folded and trimmed.

Indicia
Recognized by the US postal system as a means of showing that postage has been paid. Mailers using an indicia must have a bulk mailing permit.

Jogging
To straighten or align the edges of a stack of paper by jostling them.

Kerning
Adjusting the amount of space between letters or characters so that letter spacing appears to be in balance.

Kiss Cut
A process used for peel-off labels where a die cut is made through the face materials but not the backing.

Laminate
A means of bonding plastic film to a sheet of paper using heat and pressure.

Letterpress
The process of printing from an inked raised surface.

Lithography
The process of printing from a flat surface (such as a smooth stone or metal plate) that has been treated so that the image area is ink receptive and the nonimage area is ink repellant.

LPI
A means of measuring the fineness of a halftone screen by measuring the number of dots per inch in a halftone screen.

Makeready
Getting a printing press ready for a print run by filling the ink fountains, adjusting the paper feeder, etc.

Matte Paper
A flat, not glossy, finish on a paper or photograph.

Moire
Undesirable patterns in printed halftones caused by improperly aligned screens.

Overrun
Excess production to compensate for spoilage, future requests for materials, and other unanticipated needs.

PDF
Digital file format that allows documents to be viewed and printed independent of the application used to create them.

Perfect Binding
A method of binding magazines, books and other publications in which the signatures are glued to the cove and held together with a strip of adhesive.

Pica
Unit of typographic measure equal to 0.166 inch (4.218 mm).

Prepress
Preparing a job for print reproduction by performing necessary functions such as separating color correcting, and impositioning the pages.

PMS
Stands for Pantone Matching System, a means of specifying match or spot colors and their ink formulations.

Point
A typographic measurement system used for measuring the height of type, thickness of rules, and leading.

Printer Spreads
Pages that are set up so they are impositioned exactly where they will be when a publication is folded and printed.

Printing Plate
A surface carrying an image to be printed.

RIP
Converting digital files to bitmapped images that can be output on an imagesetter. The process is described as “ripping file.”

Ream
Five hundred sheets of paper.

Register
When each sheet enters the press from precisely the same position ensuring that all colors are in “register.”

Register Marks
Target-like symbol placed in exactly the same spot for each color plate so that proper alignment of the colors will occur on press.

Reverse
A white or noncolor image against a dark, inked, or colored background

RGB
Stands for red, green, and blue, additive primary colors that are used to create a full range of color as projected light on a computer screen.

Saddle Stitch
A method of binding by stiching through the centerfold of nested signatures.

Score
To crease or indent paper along a straight line so it folds more easily and accurately.

Separations
Reproducing a color image by dividing it into four negatives, one each for cyan, magenta, yellow, and black.

Spoilage
Paper that is recycled as a result of on-press mistakes and accidents.

Spot Color
See match color.

Spread
a.) Slightly enlarging an image to create a trap.
b.) A pair of facing pages: typically the left and right hand pages in a publication.

Stet
Latin for “let it stand.” Proofreader’s or editor’s indication that an item marked for correction should remain as it was before the correction.

SWOP
Recommended printing specifications published every few years by a committee of graphic arts professionals.

Thermography
A method of printing where a raised impression is created by heat curing a blend of ink and resin.

TIFF
Used for placing images or graphics in documents created in word processing, page layout, or drawing programs.

Trap
Printing one ink over another so there is a slight overlap of colors in order to prevent a colorless gap between adjacent colors if they are slightly off register.

Uncoated paper
Paper that has not been coated with clay.

Varnish
Coating applied to paper to give it a dull or glossy finish or to provide protection against scuffing.

Variable Data Printing (VDP)
Digital printing that allows text, graphics and images to be changed on each piece, without stopping or slowing down the process. A database connected to the print file drives the data that is changed. A main use of VDP is direct mail, where the same basic layout can be printed with a different name and address on each letter.

Watermark
A translucent impression made in a sheet of paper created during its manufacture.

Work and tumble
Printing a sheet so that the same images is produced on both sides of a sheet. When the sheet is tumbled, the opposite side of the sheet is fed through the press.

Work and turn
Printing a sheet of so that the same image is produced on both sides of a sheet. When the sheet is turned, the same side of the sheet is fed through the press.