Glossary of Printing Terms

Accordion Fold
Two or more parallel folds that open like an accordion.

ASCII
Acronym for American Standard Code for Information Interchange, a standard code used to help transfer files between different software applications or hardware devices.

Assembly Sheet
Instruction sheet for a printing job that shows the correct page sequence, including all unnumbered pages

Back Up
Printing the reverse side of a sheet already printed on one side.

Bad Break
Starting a page with a hyphenated line or "widow" (very short line); also incorrect hyphenation.

Bleed
Printed image extending beyond the trimmed edge of a page, usually 1/8 inch.

Blueline
Proof made from stripped-up negatives or positives, used as a final proof to check position of image elements, folding, color breaks, etc. All colors are indicated by different shades of blue.

Burn
Exposure made during the platemaking process. Several burns can be made to a single printing plate.

Caliper
Thickness of paper, usually expressed in thousandths of an inch (mils).

Camera-Ready Art
Finished mechanicals with page materials in position, ready to be photographed and printed.

Center Mark
Lines on a mechanical, negative, plate, or press sheet indicating the center of a layout.

Coated Paper
Paper coated on one or both sides to improve ink holdout and surface characteristics; can be glossy, dull, or matte finish. C1S (coated one side) paper is used for covers and dust jackets.

Collate
To gather sheets or signatures in a specified order for binding.

Color Bars
A strip of ink colors printed near the edge of a sheet to test various aspects of the printing process, including the ink densities.

Color Breaks
Parts of artwork to be printed in different colors . Color breaks need to be indicated on tissue overlays on mechanicals or on a hard copy dummy provided with a desktop file.

Color Key
Trade name for a proofing system in which each color to be printed appears on a separate acetate overlay and combines to simulate the finished color piece.

Color Separations
The process of separating full-color photographic transparencies or prints into the four color components needed to create printing plates in the four process ink colors of black, cyan, magenta, and yellow. Most color separations are now done by computerized scanning of the original image.

Color Transparency
A full-color transparent positive image. Also called a chrome, or slide.

Comp, Comprehensive (see also Rough)
Designer's complete mockup of an idea or concept for a printed piece.

Continuous Tone
Original photographs, illustrations, or artwork that have not yet been photographed (screened) to break the image area into dots for reproduction.

Crash Printing
Letterpress printing on carbonless forms so the image prints simultaneously on all sheets in the set.

Creep
Phenomenon of the middle pages of a folded signature extending slightly beyond the outside pages. To adjust for the creep, pages can be shingled in stripping to slightly different page widths.

Cromalin
Trade name for a color proofing material consisting of transparent layers laminated in one piece to a backing. Each layer represents the film for one color. The result is a crisp, bright simulation of the printed product.

Crop Marks
Lines near the edges of an image showing portions to be eliminated.

Crossover
Image that continues from one page of a publication across the gutter to the opposite page.

Double Bump
To print an image area twice with the same ink color to ensure smooth, even coverage of large solid areas.

Drawdowns
An ink drawdown can be provided by the ink manufacturer to show approximately how an ink color will look when printed.

Dummy
Replica of the finished piece, marked with color breaks and folds, made with the paper selected for the job.

Duotone
Photograph reproduced from two halftone negatives and usually printed in two ink colors.

Duplicators
Small offset presses that use inexpensive paper printing plates (instead of metal) and ink to reproduce images.

Emboss
A raised image created by stamping a paper sheet with a metal die.

EPS Files
Files saved in Encapsulated PostScript format. PostScript files, which contain both the page elements and the page description language for the printer, are both input and output-device independent; however, they cannot be edited or modified in this format.

Flat
A stripped-up assembly of film negatives, ready to be contacted to create printing plates.

Flop
To reproduce a photograph or illustration so that its image faces opposite from the original.

Font
All of the characters and associated spacing of one size of one typeface.

Form
One side of a press sheet.

Gutter
Space between columns of type where pages meet at the binding.

Halftones
Continuous-tone photographs or artwork that have been photographed through a screen to convert the image into dots for reproduction. Halftones can be positive or negative and on film or paper.

Hickies
Donut-shaped spot or imperfection in printing, most visible in areas of heavy ink coverage. Occur most frequently with recycled papers.

Image Area
Portion of a negative or plate corresponding to inking on paper; portion of paper on which ink appears.

Imagesetter
Digital output devices that produce high-resolution film or paper from electronic files.

Indicia
Postal permit information printed on objects to be mailed and accepted by USPS in lieu of stamps.

Makeready
All the activities required to set up the press for a pressrun, including running test sheets of paper.

Mechanicals
Prepared artboards that are camera-ready. Finished mechanicals contain art, type and other page elements, in positive form, pasted into position on the page.

Moire
Undesirable pattern in printed halftones and screen tints, usually caused by incorrectly aligned screen angles.

Negatives (negs)
A film negative version of an image area, obtained either by shooting the mechanical page with a process camera, or by running out film through an imagesetting system.

Offset Printing
Offset printing is a printing process that uses metal plates and ink; it is characterized by the use of a blanket cylinder, a rubber plate that picks up the image from the metal plate itself and then transfers that image onto the sheet of paper. In offset printing, the actual plate never directly touches the paper.

Pantone Matching System, PMS, Pantone Colors
A commercial system for specifying colors by means of numbered color samples provided in swatch books.

Position Only, or FPO
Photocopy or stat made to size and pasted to a mechanical showing how to crop, scale, and position loose art or photos.

Process Color
The four standard ink colors used in full-color printing: black, yellow, cyan, and magenta.

Rainbow
Trade name for a color proofout form a digital file. This proof requires no film output contains no dots therefore it isn't completely accurate in matching color. The result is a simulation of the printed product with a few color variances.

Register
To position printing in proper relation to the edges of the paper and other printed images on the same sheet.

Register Marks
Cross-hair lines on mechanicals, negatives, and plates that guide strippers and printers.

Reverse out, Knock out
Type or other image defined by printing the background rather than the image itself, allowing the underlying color of paper or previously printed ink to show in the shape of the image.

Scale
To identify the percentage by which images should be enlarged or reduced.

Score
To mechanically crease paper along a line so it will fold more easily.

Screen Build
An approximation of a PMS color created by printing different screened combinations of ink colors on top of each other.

Self Cover
Publication made entirely from the same paper so that cover is printed simultaneously with inside pages.

Sheetfed Press
Press that uses pre-cut sheets of paper, rather than rolls.

Showthrough
Printing on one side of the paper that can be seen when looking at the other side.

Spot Color
Colors specified in PMS inks other than the four standard process colors.

Screen Tint
A tint of either black or another ink color, specified as a percentage of black or another ink color, printed as dots of uniform density.

Signature
A press sheet folded into a series of pages to be bound. Standard signatures are 8, 16, and 32 pages.

Specifications
Complete and precise descriptions of paper, ink, binding, quantity, and other features of a printing job.

Split Fountain
Printing technique of putting two or more ink colors in a single press ink fountain, creating the effect of a blended color transition.

Stripping
Assembling negatives in flats in preparation for making printing plates.

Text Paper
Paper grade characterized by textured surfaces, such as laid, cockle, wove, etc. May also be used to describe paper used for the text portion of a publication, as opposed to cover stock.

Trap
The tiny amount of overlap between two printed areas that ensures a "butt fit" between those areas without white paper showing through.

Trim Size
Size of the printed product after the last trim is made.

UV Coating
Liquid laminate bonded and cured to the sheet with ultraviolet light.

Up
Printing two-up or three-up means printing the identical piece two or three times on one sheet of paper in one impression.

Washup
The process of cleaning a press after a press run.

Watermark
Distinctive design created in paper fibers during paper manufacture.

Web Press
Press that uses paper in rolls, rather than cut sheets.

Varnish
Clear finish applied like ink on a press that provides additional protection and sheen to a printed piece. A varnish may have a dull or glossy appearance, and may be tinted with colored ink. A flood varnish is applied to the entire page; a spot varnish is applied only to selected image areas and requires a printing plate to apply.

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