Glossary of Printing Terminology

Listed below are the common terms used within the printing industry in everyday speak as well as a few definitions and explanations that will be of great help to you. If you ever wondered what is meant when a job 'bleeds' or when a 'dummy' is needed, then here is your chance to wise up on printers' jargon.

A B C D E F G H I J K L M P R S T U V W Z

Adobe Acrobat
Plece of software that enables you to edit pdf files
Adobe Acrobat Distiller
Plece of software that enables you to create pdf files from postscript files. It provides the user with a host of options to create the pdf as, such as font and image embedding, colour downsampling etc
Adobe Acrobat Reader
Free piece of software that enables you to view pdf files and carry out simple operations. Known simply as Adobe Reader from version 6 onwards
Against the grain
At right angles to the direction of the paper grain
Alterations
Corrections and/or additions made by the customer in artwork at proof stage
Art paper
Smooth surfaced paper
Artwork
The job specification file supplied to the printer and made up of text, illustrations etc., and created nowadays using computer software

Back up
To print on the reverse side of a sheet whose front side has already been printed on
Banding
A method of packaging printed material using paper or rubber bands; A defect in the output of a graduated tint
Binding
The process of fastening papers together with wire, thread, glue, or by other means
Bitmap
An image made up of a grid of pixels or printed dots (bits), with the colour of each pixel logged on a table (map)
Blanket
A thick rubber-like mat held on a clyinder of a printing machine that transfers the printing image from the plate to paper
Bleed
Referred as occuring when the printed area extends beyond the trim edge of a page or sheet
Bold
Version of a typeface with stronger emphasis
Bond paper
Strong durable type of paper commomly used for letterheads and business forms
Bulls Eye
An imperfection in the printing process, created by an object (e.g. a speck of duct) coming between the paper and the printing surface (e.g. the blanket or plate)

Calibration
Using a fixed measurement to ensure accurate performance in a machine or process
Caliper
Paper thickness in thousandths of an inch
Carton
A container generally made from paper or board delivered by carton manufacturers to a user, either in flat or collapsed form, for assembly at the packaging point
CMYK
Abbreviation for cyan, magenta, yellow and key (black), the 4 process colours, which combined together in varying proportions can be made to produce the full colour spectrum; the subtractive primary colours used in four colour printing
Coated Paper
Paper which has received a coating on one or both sides. Art papers are coated papers, there are also cast-coated, which are high gloss papers on which the coating has been allowed to harden in contact with a highly finished casting surface. In addition,there are brush coated papers; chromo papers which are clay-coated in a separate operation from papermaking; roller-coated papers; or machine coated papers in which the paper is coated during the papermaking process
Collating
Arranging of printed sheets into the desired sequence
Colour Control Bar
A coloured strip on the margin of the sheet which enables the platemaker and printer to check by eye or instrument the printing charateristics of each ink layer
Colour Proofing
Describes a wide range of techniques which have been developed to reproduce full colour images from the film or digital data available, prior to the actual print run; thus allowing the client or printer to view the proofed result, prior to the actual print run
Compression
To decrease the size of a computer file, programs can be run that remove unnecessary information and in so doing, reduce the overall size of the file
Crease
To mechanically press a rule into heavy paper or board to enable folding without cracking
Crop
To cut off parts of a picture or image
Crop marks
Marks at the edges of an illustration or photograph to indicate the portion to be reproduced; Printed lines showing where to trim a printed sheet
CtP
Computer to Plate. This is the new technology whereby the digital file is sent directly from the imposition program to a platesetter - thus bypassing the need to output film
Cyan
One of four standard process colors - the 'blue' color

DCS
An extension to the EPS system which enables CMYK separations to be saved and read by other computer programs than the one that created it
Densitometer
Machine used to monitor the density of colour on printed material
Density
The degree of colour or darkness of an image or photograph
Density Control Bar
Found on the side of proofs and printed material, these calibration bars are a strip of tones used to ensure printing quality and consistency. On film, the strips are calibration bars, and on paper they are colour control bars
Die
Metal rule or imaged block used to cut or place an image on paper in the finishing process
Die Cutting
Cutting images in or out of paper
Distribution Rollers
These are the rollers on a printing machine that move the ink from the ducts to the plate
Dithering
A technique of simulating colours from adjacent pixels to compensate for a limited colour range
Dot Gain or Spread
A halftone dot will become larger in the transition from film to print - this has to be planned for in the reproduction process; A term used to explain the difference in size between the dot on film v paper - This change is called 'dot gain percentage', as it will always be a plus factor, ie 30% dot on film, 40% printed dot - this increase is referred to as 10% dot gain. This press dot gain must be anticipated at the film stage and the film dot size reduced to counteract the percentage gain. This is not a linear change as it varies depending on the original film dot size
DPI
Dots per Inch. This measurement indicates the quality of the resolution. The higher the number (i.e. 6000) the greater the resolution
Dummy
An example of a proposed publication, usually made out of the paper specified; A rough layout of a printed piece showing position and finished size; A sample of a proposed job made up with the actual materials and cut to the correct size to show bulk, style of binding, etc. Also a complete layout of a job showing position of type matter and illustrations, margins etc.
Duotone
A two colour halftone produced from two halftone images of the same original
Dot
An element of halftones. Using a loupe you will see that printed pictures are made many dots

EDI
Electronic Data Interchange - a term which describes any commerical data transfer
Emboss
Pressing an image into paper so that it will create a raised relief
EPS
A file format, Encapsulated PostScript, used to transfer PostScript image information from one program to another; Encapsulated Postscript File - A file that contains postscript information that can be transferred between different computer programs
Estimate
A price given to a customer based on print specifications provided by the customer. The price can change if the order specifications are not the same as the estimate specifications

Finishing
The term used to refer to all operations after printing; also the hand operations of lettering and ornamenting the covers of a book
Flush
A style of binding in which the covers and the leaves are trimmed simultaneously as a final operation; when the covers and sections are trimmed at the same time
Folioing
Numbering progressively by book openings instead of pages, the left and right pages have the same number
Font/Fount
A typeface family
Four-Colour process
Colour printing by means of the three subtractive primary colours (yellow, magenta, cyan) and black superimposed; the colours of the original having been seeparated by a photographic or electronic process; Reproduction of full-colour photographs or art with the four basic colours of ink (yellow, magenta, cyan, black)

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
Gather
To place in their correct order the sections or sheets to make up a book
GIF
Graphical Interchange Format. A graphics file usecf on the internet
Gloss
A shiny look that reflects light
Grain
The direction in which the paper fibres lie
Grammage
The weight of a material such as paper defined in grams per square metre
Greyscale
The depiction of grey tones between black and white. A greyscale monitor is able to display grey pixels as well as black and white, but not colour pixels
Gutter
The binding margin of a book; line or fold at which pacing pages meet

Hairline
A very thin line or gap about the width of a hair or 1/100 inch
Halftone
Picture with shades of tone created by varying size dots
Heat-set Drying
Drying a web or sheet of paper or board by passing it through a drying unit which forms part of the machine. Special heat-setting inks have to be used
Hickey
Reoccurring unplanned spots that appear in the printed image from dust, lint, dried ink

Image
The ink-carrying areas of a lithographic printing surface plate
Imposition
The arrangement of the pages so that they will be in correct sequence when the printed sheet is folded
Inkjet
A non-impact printing process in which droplets of ink are projected onto paper or other material, in a computer determined pattern
Insert
A piece of paper or card laid between the leaves of a book and not secured in any way
ISDN
Integrated Services Digital Network. A communications systems used to transmit large amounts of volume at relatively high speeds; ISDN uses digital signals as opposed to analogue (your normal phone line uses analogue). This means that it is ideal for carrying data and provides excellent quality speech lines. ISDN 2e is ideal for small businesses who need two or more normal telephone lines to handle their communications. Each ISDN 2e provides two channels of ISDN, each operating at 64Kbps speed. You can bond the channels together to achieve 128Kbps speed. Often used for high speed internet access, for fast file transfer. ISDN 30 is ideal for medium to large businesses. It provides eight or more channels of ISDN, each working at 64Kbps speed

Jazz
A removable computer disk, with storage capability for large amounts of data
Jpeg
Another type of graphics file format, also widely used on the internet; a format for encoding image files (mainly eps image files) to reduce file size at the expense of image quality

Kerning
Adjusting the spaces between letters
Keylines
Lines on mechanical art that show position of photographs or illustrations
Knocking Up
To make the edges of a pile of paper or board straight, regular or flush; To straighten the edges of a handful of paper flush
Knockout
To mask out an image; Because printing inks are not completely opaque, printing one ink over another will create a third colour. To avoid this, a knockout, or unprinted area, in the shape of the foreground object is left in the colour plates that make up the background. The danger is that a gap may appear between the foreground object and its background if misregistration occurs during printing

Laminating
The application of transparent plastic film, usually with a high-gloss finish, to the surface of printed matter to enhance its appearance and to increase its durability
Leading
Space between the lines of text
Letterpress printing
This is a printing method using a protruded printing surface which is in contact with both paper and ink
Lines per inch (LPI)
The number of rows of dots per inch in a halftone; The LPI is an indicator of the quality of the resolution
Lithographic printing
This is a printing method using a flush printing and non-printing surface which is in contact with paper. The non-printing areas are treated to attract water which prevents ink from attaching

Magenta
Process red, one of the basic colors in process color
Makeready
The work associated with the set-up of printing equipment before running a job; All the activities required to prepare a press for printing
Matchprint
Trade name for 3M integral color proof
Matt art
An art paper or board with a dull eggshell finish
Moire
Occurs when screen angles are wrong causing odd patterns in photographs

Pantone
Pantone, Pantone Matching System and PMS + are Pantone Incs check standard trademarks for colour standards, colour data, colour reproduction and colour reproduction materials, and other colour-related products and services, meeting its specifications, control and quality requirements
PDF
Portable Document Format (PDF) is an open standard from Adobe Systems. The key feature being cross-platform independence. The file itself contains all the fonts, graphics, and page layout information necessary for printing
Perfect-binding
Style of threadless binding in which the leaves of a book are held together at the binding edge by glue or synthetic adhesive and a suitable lining
Perfecting
Process of printing on a sheet-fed printing press that prints both sides of a sheet in one pass
Posterisation
This is a form of graduation, where it is desirable to have bands of colour created marking out the changes in shade
PostScript
A Page Description Language (PDL) developed by Adobe, which describes the contents and layout of a page. PostScript also serves as a programming language whereby the PostScript code is executed by a PostScript RIP in the output device in order to produce a printout or film containing the page
Prinergy
PDF based prepress workflow solution for managing prepress and plate production
Proof
A copy of a document for checking prior to printing

Ream
Five hundred sheets of paper
Register
The printing of two or more plates in juxtaposition so that they complete a design if printed on the same side of the sheet or back up accurately if printed on opposite sides of the sheet
Register Marks
Marks placed in the same relative position on sets of printing plates so that when the marks are superimposed in printing the work falls into correct position; Cross-hair lines or marks on film, plates, and paper that guide strippers, platemakers, pressmen, and bindery personnel in processing a print order from start to finish
Resolution
The number of dots per inch (dpi) in a computer-processed document. The level detail retained by a printed document increases with higher resolution
RGB
Red, Green, Blue. These colours make up an additive form of the four printing colours CMYK. RGB scans should always be converted to CMYK for correct output
RIP
Raster Image Processor. This is the technology that ensures that vector data is correctly processed by output devices; the process of making printing negatives from PostScript files created by desktop publishing software

Saddle-stitch
A binding process in which a pamphlet or booklet is stapled through the middle fold of its sheets using saddle wire; To stitch with wire through the back of folded work
Score
To partially cut/crease with a rule into heavy paper or board to break the grain and so enable easier folding; A pressed mark in a sheet of paper, usually a thick paper, to make folding cleaner and easier
Section
A folded sheet of paper forming part of a book; sections are sometimes made of insetted folded sheets of four, eight, sixteen or more pages
Self-cover
When the paper used inside a booklet is the same as that used for the cover and is generally printed on the same press run
Set-off
When ink from a printed sheet marks the underside of the sheet above it
Shrink wrapping
Method of packing printed products by surrounding them with plastic, then shrinking by heat
Signature
A sheet of printed pages which when folded become a part of a book or publication; folded, printed paper forming a section of a book; usually in a multiple of four, and more often a multiple of eight; The consecutive number or letter which is printed at the foot of the first page of a section to enable a binder to check the position and completeness of the sections. Signatures are often indicated by printing a rule in the back of each section so that when the sections are folded and gathered the signatures appear 'stepped' on the back fold
Software
The programs that enable the computer to perform its tasks
Spine
The binding edge of a book or publication
Spot Colour
Any area of colour that is not printed using a CMYK process set; coloured areas reproduced using self coloured inks, such as PMS (Pantone) inks; A colour that is printed from a specially pre-mixed ink, usually identified by a Pantone number
Spot Varnish
Varnish used to hilight a specific part of the printed sheet
Stock
Material (paper) to be printed on

TIFF
Tagged Image File Format. Images are saved in this format so that they can be exchanged between different computer applications. It is very commonly used in desktop publishing
Tints
A shade of a single color or combined colors; Mechanical shading in line areas, normally available in 5% steps from 5% to 95%
Transparency
A positive photographic slide on film allowing light to pass through
Trapping
The ability to print one ink over the other; When multicolour publications are printed on an offset press, slight misalignment of colour plates or shifting of paper can result in gaps between adjacent objects of colours. Trapping is the process of intentionally overlapping the adjacent colours to compensate for misregistration and prevent these gaps
Trim Size
The final size of one printed image after the last trim is made

Up
Printing two or three up means printing multiple copies of the same image on the same sheet
UV Coating
Liquid laminate bonded and cured with ultraviolet light. Environmentally friendly

Varnish
A clear liquid applied to printed surfaces for looks and protection. (UV coating looks better)
Varnishing
To apply oil, synthetic, spirit, cellulose or water varnish to printed matter by hand or machine to enhance its appearance or to increase its durability

Washup
Removing printing ink from a press, washing the rollers and blanket. Certain ink colours require multiple washups to avoid ink and chemical contamination
Watermark
A distinctive design created in paper at the time of manufacture that can be easily seen by holding the paper up to a light
Web
A roll of printing paper
Web offset
Reel-fed offset litho printing. Three main systems of presses exist blanket-to-blanket in which two plate and two blanket cylinders per unit print and perfect the web of paper or board; three-cylinder system in which plate, blanket and impression cylinders operate in the usual manner to print one side of the paper or board; and satellite or planetary system in which two, three or four plate and blanket cylinders are arranged around common impression cylinders to print one side of the web in several colours
Web press
The name of a type of presses that print from rolls of paper; Presses which are fed by paper from a reel as distinct from separate sheets
Wire-O
A bindery trade name for mechanical binding using double loops of wire through a hole
Wire-O binding
A method of wire binding books along the binding edge that will allow the book to lay flat using double loops
Work-and-tumble
To work on both sides of the sheet gripping on both edges using a perfecting press. The paper is turned over automatically inside the press, as opposed to work-and-turn where the paper is manually turned and then run through the press again; Printing one side of a sheet and turning it over from the gripper to the tail to print the second side using the same side guide and plate for the second side
Work-and-turn
To print on the entire area of both sides of a sheet by using the same gripper edge. One side is printed, the paper is turned over and run through the press again
Wove paper
A paper having a uniform unlined surface with a smooth finish

Zip
A removable computer disk, with storage capability for large amounts of data