Glossary of Printing Terms
If you’re not familiar with printing terms, hearing them for the first time can sound like gobbledygook. As print management professionals, printing terminology is like a second language to us. We’re always happy to explain the various definitions and meanings but we thought it’d be useful to provide a comprehensive glossary of printing terms and phrases for you to get your head around.
Scroll down the page, or if you know what you are looking for, click on a letter in the Alphabetical index.
> A binding term for two or more parallel folds that open like an accordion. Brochures and maps often use accordion folds.
> A high quality, transparent sheet of plastic commonly used plastic commonly used as a layer in multi-layer artwork or composition. Acetate is also used for overhead transparency printing.
> Red, green, and blue light, which produces white light when combined.
Compare with subtractive primaries.
> Series of trimmed sizes in the ISO international paper size range.
> Style of binding where the leaves of a book are held in position at the spine by glue or synthetic adhesive. Also called ‘limp’, ‘perfect’ or ‘thermoplastic’ binding.
> An instrument which uses compressed air to blow a current of air over an ink reservoir. The air atomises the ink and ejects it at the image. It is
used by artists to obtain graduated effects artwork.
> A stable, acid free paper used for products that must resist deterioration and preserve their images for as long as possible. Archival photographs, high-quality books, and fine art prints are made
on alkaline paper.
> Colour matching system commonly used in the production of newspaper and magazine applications.
> A rough uncalendered paper being light in weight with bulk. Normally
used for book printing.
ANTI SET-OFF SPRAY
> A powder which is sprayed over the printed sheets during the printing process which keeps the sheets separated and reduces set-off.
> (Apple Desktop Buss) connects keyboard, mouse and other devices.
> A network (cables linking computers and printer together) that allows
the transfer of data between machines.
> Paper which has received a coating of china clay. The coating may be
matt or gloss.
> A visible indication (defect) in an image, caused by limitations in the
reproduction process (hardware or software).
> Corrections to proofs, made by the author, that alter the original copy.
The costs of making such alterations are usually charged in contrast to the printers’ errors or house corrections.
AUTOMATIC IMAGE REPLACEMENT
> A process by which high-resolution image files are automatically
substituted for low-resolution placeholders at output time.
> American Standard Code For Information Interchange. A standard format for representing digital information in 8-Bit chunks.
> Series of trimmed sizes in the ISO international paper size range.
> Printing the reverse side of a sheet of paper, to which one side has previously been printed.
> A lightweight or typewriting paper, white or tinted, made in a range of
weights from 45gsm to 60 gsm.
> A visible stair-stepping of shades in a gradient.
> The tendency of pages toward the middle of a signature or of a
saddle-stitched book to creep outward.
> The method of holding together the signatures of a book. The process
> The smallest unit of information in a computer (Binary Digit).
> Unit of measure relating to a device’s ability to allocate more than one
colour to a pixel or screen dot. In practice, the number of colours a
device can display or input (in the case of scanners).
> Image composed of individually-referenced dots. All continuous-tone
images (paintings, photographs) are measured, manipulated and stored
in this way.
> An image formed of a rectangular grid of Pixels.
> The blanket is a fabric coated with a rubber or synthetic coating which
is wrapped around the blanket cylinder. The print image is transferred
on this blanket from the printing plate to the paper.
> The allowance on a drawing or printing plate which extends the plate
beyond the trimmed or finished size to ensure a clean cut-off. Usually
> A colour value from one pixel unintentionally appearing in adjacent
> The amount by which a bleed colour or image must extend beyond the
specified trim in order to allow for variances in cutting and folding.
> A half tone, line or duplicate printing plate.
> A one-colour proof generally used to check imposed film.
> A writing or typewriting paper, similar to bank paper, but heavier, and
usually supplied in 60 gsm and over.
> Any sheet in its basic size – not folded or cut.
> Fold formed when the front edge of a moving sheet of paper is stopped
by a plate, allowing it to buckle at a predetermined point.
> A unit of measure equal to eight bits of digital information (23).
The standard unit measure of file size. See also megabyte, kilobyte,
> Series of trimmed sizes in the ISO international paper size range.
> Computer-aided design.
> A roller or series of rollers used in the finishing operation of paper
manufacture.The pressure exerted contributes to the finish and
smoothness of the paper.
> A method of adjusting scanners, video monitors and output
devices to a defined standard so that each represents colours
accurately and predictably.
> On a negative, proof or printed piece, a strip of tones used to check
> The thickness of a material.
> Any artwork or type that is ready to be prepared for printing.
> Abbreviation for ‘capital letters’.
> A tough, opaque paper of a cream shade and often with a rough
> The binding of printed books
, which may include leather cloth or other
covering materials. The finished book is usually stiff as opposed to limp
see ‘adhesive binding’.
> A single layer of information in an electronic graphics file. In a
CMYK file, channels may represent the information for each of the
> A cheap board made from mechanical wood and waste materials. It is
used unlined for case binding, rigid boxes, backs of pads, showcards
etc. and with a white lining paper for cartons and display material.
> An abbreviation for cyan, magenta, yellow, and black, the four colours
used in process-colour printing.
> A half-tone screen used in preparing illustrations for newsprint and
other less demanding work.
> Paper which has received a coating on one or both sides. Art papers
and board are coated. Other coated papers include cast-coated
or high gloss paper; brush coated;chromo papers etc.
> To put sections or pagination of the sections of a book in the correct
sequence so that they are in the correct sequence for binding.
> An unwanted dominant colour present in the original image or in
COLOUR CASTCOLOUR SEPARATIONS
> The process of separating the colours of a picture by coloured filters.
This may be done with a camera or electronic scanning.
COLOUR CONTROL BAR
> A coloured strip in various densities located on the back edge of the
sheet, which enables printers and platemakers to check print quality
COLOUR CONTROL STRIP
> An image included on a press sheet to indicate printing conditions.
> The process of adjusting an image to compensate for scanner
deficiencies or for the characteristics of the output device.
> The range of colours that can be reproduced using a certain process.
For example, the colour gamut of an RGB monitor is much broader
than that of CMYK inks on paper.
COLOUR MANAGEMENT SYSTEM (CMS)
> A software system used to ensure colour consistency among different
input and output devices so that printed results match originals.
> A utility for specifying colours on the monitor.
> A representation of what the final printed composition will look like.
The resolution and quality of different types of colour proofs can
> The division of an image into four separate colours for printing. Each
colour is represented on a piece of film as lines of dots at specific
angles. When overlaid, the dots on each level form tiny rosette patterns
that simulate shades of colour when seen at a distance.
> Four colour printing but with one of the standard CMYK inks replaced
with a Pantone/Special colour – say yellow for instance to enable
establishments to match corporate colours exactly without the cost
of a fifth working.
COMBINATION LINE & HALFTONE WORK
> Line and tone (eg words and pictures)together on one printing plate.
> Paper folded in consecutive opposite directions.
> A proof supplied to a printer to document the colour results expected
> A web of paper with sprockets down the side. This is often fan
folded and perforated after printing so that the finished sheets can be
personalised on a sprocket fed laser printer.
> A press which can print (perfect) either a single colour on both sides or
two colours one side.
> Any material furnished by the customer (typescript, photographs,
drawings etc.) to be used in the production of printed matter.
> To mechanically press a rule into a heavy paper or board to facilitate
accurate folding without cracking.
> A stochastic or frequency modulation screening technology available on
PostScript RIPs from Agfa.
> A full colour image created by a photographic process from the
four colour separations, which gives printer and client an accurate
comparison against the printed work.
> Lines that indicate the boundary of camera ready artwork. These marks
are used to trim the page to its desired size after printing.
> A colour or image that crosses the gutter of a spread in a finished
> Two folds at right angles to each other.
> (Continuous Tone) A file format used for exchanging high-level
> (Computer to Plate) Digital information sent directly to printing plate
from the computer via a RIP as opposed to computer to film.
> An ink colour that is premixed to match a specified hue. Custom
colours are generally used to reproduce colours that are not possible
to match using the four-colour process, as spot colours in two or
three colour jobs, or as additional colours in duotones and tritones.
Some vendors of custom colour systems include Pantone, TruMatch,
FocolTone, and Toyo.
> The maximum size of an image produced by a web press.
The dimension is determined by the circumference of the printing
> An irregularly shaped illustration or silhouette.
> A press on which the type forme is flat but the printing action is made
against a revolving cylinder.
> A shaped cut, such as the window in an envelope.
> (Desktop Colour Separation) A PostScript image file format for
separated files. A DCS file includes five parts: one for each of the
process colours plus a PICT preview that represents the image on the
computer screen. The separated files are automatically substituted at
> A device sensitive to the amount of light transmitted or reflected by
paper or film. It is used to check the accuracy, quality, and consistency
> The degree of opacity of a photographic image on paper or film.
> A file, used with a colour management system, that describes the
colour characteristics of a properly calibrated input or output device.
> Storage medium: floppy (800K or 1.44Mb), hard (20Mb to 2Gb),
removable (44Mb to 200Mb) or optical (up to 650Mb).
> Type boldly displayed as on title pages and headings, as distinct from
solid text or body matter.
> Sizes of type usually larger than 14 point and for display matter.
> The rollers on a printing machine which transfer the ink evenly from a
duct to the plate.
> The amount by which a halftone dot grows between the film, the plate,
and the press sheet. An inevitable part of the printing process.
> (Dots Per Inch) A measure of the output resolution produced by
printers, imagesetters or monitors.
> A piece of software that tells the Mac how to communicate with,
or operate another piece of hardware, most commonly a printer or
scanner. System folders contain a printer driver, if they do not then you
> An imagesetter in which the film or paper medium is wrapped around
a circular drum during exposure.
> A scanner in which the original is wrapped around a circular drum
during the scanning process.
> In photogravure, the knife blade in contact with the printing cylinder
which removes excess ink from the non-image areas before printing.
> A better quality coated paper
which has two coatings on each side.
> A lightweight cover board which is attached to the sewn book by gluing
at the spine.
> The ink reservoir on the press which supplies the inking rollers.
> An unprinted sample of a proposed job made-up with the actual
materials and cut to the correct size to show bulk, style of binding, etc.
> Two colour half-tone made from monochrome original, the second
colour being used as a tint.
DYE SUBLIMATION PRINTER
> A type of digital colour printer that creates continuous-tone, glossy
images by heating CMYK dyes until they turn to gas (sublimate).
> (or Blue Proof) – An inexpensive proofing method used at the
platemaking stage as a final check.
> The range of tones from light to dark that is captured in an electronic file.
> The mechanical removal of the non-image areas by a stylus controlled
by a light-sensitive cell scanning an original photograph or drawing.
> The process of obtaining a raised image
on paper or board. This is
usually achieved by producing a male and female block and passing
the paper between the two surfaces under pressure. Where there is
no printed image, the process is called ‘blind embossing’.
> The coating of light-sensitive material on a piece of film.
> This specifies a readable film image with the emulsion side facing away
from the viewer. The printer usually decides whether emulsion should
be up or down.
> Lining sheets used at each end of a book
, used to fasten the end
sections to a case bound cover.
> (Encapsulated PostScript) A file format used to transfer PostScript image
information from one program to another. The file includes PostScript
code plus a low-resolution (PICT) representation of the image.
> A fold giving the same effect as a fan – a left hand fold followed by a
right hand fold and then repeated. Also known as a Concertina Fold.
> In process engraving, the coloured gelatin or glass placed in front of the
camera lens to separate colour.
> Processing effects used to manipulate photographic images to control
colour or contrast or to add special effects.
> A general term describing the processes, (such as scoring, folding,
die-cutting, and embossing) that printed work goes through between
the press and shipping.
> A scanner in which the original is placed on top of a glass plate,
past which a light source and a CCD sampling device is passed.
Recent advances in technology have dramatically increased flatbed
> A letterpress type printing process which uses a rubber or plastic plate.
> A colour matching system which consists of 763 achievable CMYK
colours. Focaltone helps avoid prepress trapping and registration
problems by showing the overprints that make up the colours.
> A folded sheet supplied by the printer to demonstrate imposition
> The page number.
> A typeface.
> In electronic publishing, the data files that supply the graphic
information used to create a certain type style on the screen and
> The edge of a book furthest from the spine.
> Type and printing material locked up in a metal chase ready for printing
or duplicate moulding.
> A printing machine which prints one side of a sheet in four colours as it
> Colour printing by means of the three primary colours – yellow,
magenta, cyan plus black superimposed; the colours having
been separated by electronic scanning or photographically using
FOUR-COLOUR PROCESS INKS
> Inks used for four-colour process printing, ie yellow,magenta, cyan
FREQUENCY MODULATED SCREENING
> See Stochastic screening.
GSM (or g/m2)
> Abbreviation of grams per square metre. A method of indicating or
measuring the substance of a sheet of paper on the basis of weight in
grams per square metre.
> The relationship between the tone values in an image file to the tone
values produced by an output device.
> Compressing or expanding the ranges of dark or light shades in an
> A representation of gamma used in many image processing
applications, in which input tonal values are represented on the x-axis
and output values are represented on the y-axis.
> A feature of some image processing software using colour
management systems which warns the user when an image’s colours
cannot be reproduced on a specified output device.
> A fold which turns in on itself from both edges to the centre.
> To place in their correct order the sections to make up a book or leaves
of a multipart set.
> (Gray Component Replacement) A technique for reducing the amount
of cyan, magenta and yellow in an image and replacing them with an
appropriate amount of black. See also UCR.
> (Graphics Interchange Format) An electronic image format widely used
for electronically published images. Pronounced jiff.
> (Gb) A unit of measure equal to 1024 megabytes (Mb).of data.
> A smooth transition between shades.
> The extent to which an overall granulated pattern appears in a
photograph, due to chemical and physical characteristics of the film,
paper, or development process.
> The perceptible degrees of black below 100% coverage, usually
256 different shades. Grayscale monitors display distinct gray tones
and one-bit black and white, and usually offer sharper images than
> In lithography, the mechanical roughening of the surface of a litho plate
to retain water. In printing the treatment of paper or board to give a
linen, leather or other texture to the surface.
> Full name Rotogravure
, a printing process which uses a metal plate
etched with a negative image in the form of diamond shaped cells.
> The area at the front edge of the sheet which must be left unprinted
to allow the machine to pull the sheet through.
HALF SHEET WORK
> (see work and turn).
> A method used in printing to create the effect of continuous tones by
varying the size or density of dots. See also lpi and screen angles.
> A pattern of dots of different sizes used to simulate a continuous tone
photograph, either in colour or black and white.
> A dot in a halftone screen that has smooth, crisp edges.
> Six colour printing using enhanced cyan, magenta, yellow and black
inks with the addition of green and orange giving very vibrant results
and the ability to match 90% of Pantone colours.
> Photoshop plug-in used in the production of producing images with six
HiFi COLOUR PRINTING
> Is standard colour printing with the addition of one or two additional
colours as part of a colour halftone e.g. to enhance an image – say a
or silver in a jewellery brochure.
> The whitest part of a half-tone when printed.
> The lightest part of an image, usually white and nearly white portions.
> In printing, a spot on the press sheet caused by dirt on the substrate or
> A colour model based on three coordinates: hue, lightness (or
luminance) and saturation.
> A colour model based on three coordinates: hue, saturation and value.
> A colours wavelength of light in its purest state (without the addition of
white or black).
> Corrections to proofs, other than those made by the author.
> Software used in the production of Hexachrome separations for six
> Within the Finder, small on-screen picture representing an application,
file or volume.
> Upper high-resolution printing with resolutions from 1200dpi upwards.
> A PostScript device used to expose digital information at high
resolution onto film, paper, or plate substrate.
> A printing paper heavily loaded with china clay and highly finished,
but cheaper than art paper.
> A personalisation method using a print head and ink ribbon, similar
to an old fashioned typewriter. Now largely superseded by ink jet and
> The process of arranging the film for the pages of a book into the
correct order for platemaking.
> To plan film of pages etc. into the correct position prior to litho
> Plans for the arrangement of the pages of a book so that they will
follow in correct sequence when folded.
> A list or marked-up sheet showing the order that pages should be
imposed on each film flat for a job.
> The pressure of the plates and type in contact with the paper at the
moment of printing.
> A line of type set over to the right of the normal margin used for
quotations or sub-headings.
> The total percentage of inks at a certain point on a printed piece.
Ink coverage that is too heavy may impede proper ink trapping and
drying. UCR or GCR may be used to reduce ink coverage in four-colour
INK JET PRINTER
> A digital printing method that creates black and white or colour images
by spraying microscopic dots of ink on the page. Quality can range from
fairly low to extremely high, depending on the process and device used.
> Extra printed pages inserted into printed pieces.
> Modern printer technology that works by spraying tiny particles of ink.
> The way an application presents itself on screen and is used; or
> Some camera and scanner CCDs capture lower optical resolutions and
use interpolation to calculate new pixel locations – they take an average
from say pixel A and pixel B and insert a pixel C, this can be detrimental
to the final quality and clarity of an image.
INK JET PRINTING
> A printing process that uses a jet of ink droplets deflected on to the
paper to form images. Mostly used for personalisation, where it is
quicker and cheaper than laser, although not such high quality.
> Where the product is made continuously from web, through the printing
press and finishing line in one operation.
> Paper or card inserted between the leaves of a book or brochure and
not secured in any way.
> The insertion of one printed section inside another prior to binding.
> Any printing process from a recessed image.
> A patch up sheet between the plates and the mount to increase
printing pressure in the darker tones and also relieve the pressures in
> The placing of sheets of paper between printed sheets as they come
from the machine to prevent set-off.
INTERNATIONAL PAPER SIZES
> These are based on a rectangle whose sides are in the ratio of 1 to the
square root of 2. AO is trimmed and measures 841 x 1189mm, RAO is
untrimmed and measures 860 x 1220mm and SRAO (for work which
bleeds) measures 900 x1280mm.
> A mechanical typesetter which casts the characters in one line as a
> The even and equal spacing of words to a predetermined measure.
> (Joint Photographics Experts Group) Refers to a set of standards
developed by this group for compressing digitised images.
> Lines on drawings to indicate to the process worker areas for
tint-laying, painting up, etc.
> (K, KB) 1024 bytes of digital information. Abbreviated and referred to
> A fold created by a blunt straight edge plunging down into the middle
of a flat sheet.
> A shape or object printed by eliminating (knocking out) all background
colours. Contrast to overprinting.
> To make the edge of a pile of paper straight and regular or flush.
> A pigment-less varnish applied on or off press to give a gloss finish to
the work.Often dried or cured by infra-red or ultra-violent radiation.
> A fine quality paper in which the smooth wove surface is replaced by a
series of translucent lines about 1 mm apart crossed at 90 degrees by
lines 25mm apart . These are created by a wire roller, called a Dandy
Roll, on the papermaking machine.
> The application of transparent plastic film, usually with a high gloss
finish, to the surface of a printed sheet to enhance its appearance and
to protect the surface of the paper or board.
> An off-press proofing method in which the film separations are exposed
in contact with CMYK film, which is laminated in register onto a backing
substrate to simulate the printing process.
> (Local Area Network) A group of connected computers in a relatively
small area that share access to printers and other peripheral devices.
> Oblong leaf, folded printed sheet, or book, having its long sides at head
and foot. The opposite is called ‘portrait’.
> Highest-quality non-impact printer technology.
> A type of digital print in which toner is heat-fused onto plain paper.
> A proof created on a desktop laser printer.
> The position of print on a sheet of paper. Lays (front and side) the
guides to which paper is fed before being printed or folded. Lay edges
– the edges of a sheet which are laid against the front and side lays.
> A binding method that uses a two-part spine so the bound book laysflat
> Single sheet of paper on which can be printed two pages.
> (Light Emitting Diode) sensor. Sometimes referred to as photodiode
sensors, LEDs use a solid-state semiconductor as a light-sensitive cell.
Like CCDs, LED scanners are very durable since they use no filaments,
tubes or gas to convert light into electrical charges and generate very
> The original printing process where a raised image is used to transfer
ink to the paper by direct contact under pressure.
> The fine spacing between characters in a word of caps to give optical
balance or improve legibility.
LINEAR or SCANNING ARRAY
> A linear array, used in most desktop scanners and some digital
cameras, contains a single row of pixels that are moved (scanned)
in thousands of incremental steps by a small electric motor as light
is recorded. The arrangement allows for higher resolution recordings
using fewer pixels.
> A continuous strip of glue applied from a narrow nozzle.
> A finish impressed on paper to make the surface resemble linen, usually
produced by passing the web between engraved cylinders. Other
patterns can be given to paper by embossing, eg coral, eggshell etc.
> A mechanical typesetter which casts characters in one line as a slug.
> A process in which the printing
and non printing areas are on the
same plane, and the paper makes contact with the whole surface. The
printing part is treated to receive and transmit ink to the paper, the non
printing surface is treated to attract water, thus rejecting ink from the
> Clay or mineral fillers used in the finishing of a paper to produce an
opaque smooth sheet.
> Paper fibres tend to align themselves in the Machine Direction. Long
grain follows the long edge of the sheet.
> Small letters of the alphabet as distinct from capitals (Caps).
(Lines Per Inch) A measure of the frequency of a halftone screen (usually
ranging from 55-200). Originally, halftones were made by placing an
etched glass plate over an image and exposing it to produce dots. LPI
refers to the frequency of the horizontal and vertical lines.
> (Look-Up Table) The table of available colours a computer uses to
approximate a colour that falls outside of its range.
> The length of the paper web and the direction in which the cellulose
fibres tend to lie due to the motion of the papermaking machine. The
sheet is stronger in the machine direction.
> Paper coated on the papermaking machine.
MACHINE OR MILL FINISHED
> Finished on the machine, but not supercalendered.
MACHINE OR MILL GLAZED
> Term used for a large range of papers which are characteristically rough
on one side, highly glazed on another such as poster papers.
> The operations involved in preparing a printing machine to run.
> The assembly of type and plates into pages.
> The inactive area of a bitmapped image that will not respond
> An art paper with a flat as opposed to a gloss finish.
> Width of type area in 12pt ems (picas).
> Any paper containing a proportion of mechanical wood pulp,
sometimes specified as ‘part mechanical’.
MECHANICAL WOOD PULP
> Produced by grinding wood mechanically; used in cheap papers, such
as newsprint, and combined with larger proportions of chemical wood
pulp for better qualities.
> (MB) A unit of measure of stored data corresponding to 1,024 kilobytes,
or 1,048,576 bytes of digital information.
> An original in one colour only.
> The colours or gray tones in an image that lie between the brightest
and darkest shades (highlights and shadows). Tonal values that are
midway between highlight and shadow (a 50% black, or level 128 in
> A device that translates digital information into signals that can be sent
over phone lines.
> An undesirable artifact produced in printing when halftone screen
patterns become visible. Often caused by misaligned screens.
Moiré can often be avoided by changing screen angles or using
> The process of correcting the colour rendition settings of a monitor to
match selected colours of printed output.
> A black and white display with no gray tones.
> Uneven ink coverage in solid areas of a press sheet. Usually caused by
improper ink and water balance.
> The main circuit board of your Mac, which is also its brain holding
central processing unit and all other necessary circuits; the
> A form of bookbinding
where the sewn thread on the spine of a section sewn block is exposed to use as a design feature. This method is the same as section sewing but can be sealed invisibly with clear adhesive and trimmed, or the threads can be left completely loose. Separate Covers can be sewn onto the original book block (Sussex Bound), or can be tipped on using a thin line of adhesive.
NATIVE FILE FORMAT
> Native file formats are created by software vendors to provide faster,
more efficient processing or access to special, proprietary tools
> Irregularly shaped patterns, similar to oil on the surface of water, that
appear in a colour separation. They are caused by the varying amounts
of air between the canning cylinder and transparency surfaces as they
come into contact. The light refracts into a rainbow pattern as it passes
from the cylinder through the air pockets to the transparency. This is
avoided by applying a coat of oil (to make airless contact) or a thin mist
of powder (to prevent any contact) between the two surfaces.
> Type of fast internal interface.
> A prepress proof that simulates the printing process, not on a printing
> The most common method of printing, in which the image is transferred
from a reverse-reading plate to a positive-reading blanket, and from
there to the substrate.
> Any finishing process which takes place separately from the printing
> The lithographic method of printing by which the ink is first transferred
(or offset) from the plate to a blanket and then transferred to the paper
OPTICAL CHARACTER RECOGNITION
> (OCR) Method of scanning type and intelligently recognising it as text.
> Type of storage technology based on lasers.
> The number of pixels per inch (ppi) in a scanned image that can be
created by direct samples. In some scanners, an effective resolution
greater than the optical resolution is produced by creating extra pixels
> As command key. Sometimes marked ‘alt’.
> Artwork or photography used to create reproductions that eventually
will be printed.
> Processed optical or electronic data transferred to another device such
as a secondary storage unit, a laser printer, an electronic manipulation
station, or an analog or digital proofing device.
> In printing, a mechanical or hand cut sheet used on the machine
cylinder to reduce or increase local pressure at the point of printing
contact. In studio or process work, a flat over the original drawing
indicating areas for tints etc or giving special instructions to the
> An off-press proofing method in which the film separations are
exposed in contact with CMYK film, which is taped in register onto
a backing substrate.
> Printing over areas already printed. Contrast to knockout.
> Type matter which does not fit the design and requires a reduction in
the number of words, or reduction in word or letter spacing.
> The quantity produced of a printed job above that which was ordered.
A percentage of overs can usually be charged by the printers.
> A mono copying process involving ammonia, which produces an
image in dark bluish purple on a light background. The original
‘blueprints’ were produced by Ozalid. Cheaper for checking plate
layout than Cromalin.
PANTONE COLOUR MATCHING SYSTEM
> A proprietary system that supplies colour swatches for designers and
matching inks for printers, used to define and print specific colours.
The industry standard for non-process colour.
PART MECHANICAL PAPERS
made from a combination of chemical and mechanical wood
pulp often having a creamy appearance.
> Artwork pasted up as copy for photographic reproduction.
> A glue laid down by a plate, so that the glue follows a given shape or
is kept clear of certain areas.
> A perforation in other than a simple straight line. Often produced in a
similar way to a die cut, except no paper is removed.
> A binding method where the binding edge of a book or magazine is
ground down and coated with a fast drying glue. Then a flexible cover
is attached, creating a squared-off backbone.
> Printing both sides of a sheet on one pass through the machine,
or printing the second side of a sheet;- backing-up.
PERFORATING AT PRESS
> To perforate a job on the printing machine by means of a
> A line of cuts or punches which allows paper to be torn off easily
– for instance, to remove a reply card.
> A method created by Kodak for scanning and storing photographic
images on CD-ROM.
> The smallest ‘particle of light’.
> The setting of typematter by means of a photographic process, as
opposed to hot metal typesetting. There are 12 points to a pica and
approximately 6 picas to an inch.
> (4.23mm ) Name of the standard unit of measurement in the point
system, the correct term is 12pt (4.23mm).
> A common format for defining bitmapped or object-oriented images on
the Macintosh. The more recent format (PICT2) supports 24-bit colour.
> The PICT component of DCS and EPS files, used to represent the
image on screen during page layout.
> Particles that absorb and reflect light and appear coloured to our eyes.
The substance that gives ink its colour.
> (Picture Element) The smallest distinct unit of a bitmapped image
displayed on a screen.
> The metal (usually aluminium), plastic or paper plate carries the printing
image on a litho press. This is brought into contact with the ink which is
transferred by means of a blanket cylinder to the paper or board.
> The cylindrical surface on a rotary printing press which carries the plate.
> A fold created along the web by a blade similar to a plough
> (Pantone Matching System) A commonly used system for identifying
specific ink colours.
> A typographic standard measure based on the pica (4.23mm) to which
other measurements are related. In measuring type, 1 points is 1/12 of
a pica or 1/72 of an inch. In other words, there are 12 points to a pica
and 72 points to an inch.
PORTABLE DOCUMENT FORMAT
> Formats that allow any document to be saved, opened and viewed
without the original application used to create the file. One example is
> A software language created by Adobe Systems for describing graphic
information. It has become a standard in electronic publishing at all
levels. The key feature of PostScript is device independence, allowing
different output devices from different manufacturers to print the same
file in more or less the same way.
> (Pixels Per Inch) A measure of the resolution of scanned images. The
finer the optics of the scanner, the higher the scan resolution.
> A printing plate with a light sensitive coating, which on exposure to a
light source, through negative or positive film retains an image.
> A collective term for the steps taken to prepare original artwork
for printing. More and more, these steps are being carried out by
> A proof run on a press, using the printing inks and substrate for the
> In printing, yellow, magenta and cyan. In light red, green and blue.
> The four colours (cyan, magenta, yellow and black) that are combined
to print a wide range of colours. When blended, these reproduce only a
small portion of all the colours found in nature, but they can reproduce
the widest range with the fewest inks when printing. See also CMYK.
> A set of printing plates made in half-tone to produce a wide range
of colours and shades. Usually three or four colour process, yellow,
magenta, cyan and black.
> A set of proofs showing each colour individually and in register.These
proofs act as a guide for the printer and his customer.
> A reasonably accurate sample of how a finished piece is intended to
look. Proofs can be in black and white or colour.
> A grayscale image printed with four colours to achieve greater tonal
range or to create a special effect.
> Tonal values midway between the highlight and midtone points (a 25%
black, or level 64 in 24-bit colour).
> Major extension of QuickDraw, allowing new printing and imaging
techniques; optional user installation; requires high RAM overhead.
> (random access memory) The memory a computer uses to store the
information it is using at any given moment. The information in RAM
is lost when the power is turned off.
> The conversion of image data into a pattern of dots by an imagesetter
for the production of negative or positive film or paper.
RASTER IMAGE PROCESSOR
> Software that translates electronic file data into an array of dots
(a bitmap) that can be output via an imagesetter marking engine.
> Marks placed on the artwork to assist the planners and machine
minders to print the image in the correct position.
> Small cross-hairs on film used in the alignment of negatives.
> The alignment of different films or printing plates to produce one
> Instrument used to measure the amount of light reflected by an image
REMOVABLE CARTRIDGE DRIVE
> A device for storing electronic files in which the information is
electronically encoded on a magnetic disk that can be removed for
transport or storage.
> Known as Repro, the process of producing four colour separations
from artwork so that plates can be made.
> Resolution is a measure of the clarity, sharpness and fine detail that
a camera, scanner or output device can record. Image resolution,
sometimes called scan resolution, scan rate or sampling rate, defines
the maximum size of reproductions. Input device resolutions are
expressed as pixels per inch (ppi) values, but output device
resolutions may be expressed as ppi, dots per inch (dpi), or lines per
inch (lpi) values.
> Type set in a reverse field, such as white type on a black background.
> Red, Green and Blue. A colour model used for scanners, computer
monitors, and other light-based media, based on red, green, and blue
as the primary colours.
> The splitting off a a strip of paper from the web, which is then brought
back to join the original. Used to form separate pieces inside a one
piece sealed outer.
> (Raster Image Processor) Part of an output device that rasterizes
information so that it may be imaged onto film or paper.
> A method of folding where the paper is wrapped around itself at
> The pattern created when all four colour halftone screens are placed at
the traditional angles.
> Printing from curved plates.
SADDLE (WIRE) STITCHING
> To stitch with wire through the back of folded work in order to produce
> Measure of how vivid a colour is.
> The amount of gray in a colour. The higher the gray content, the lower
> An electronic device which scans across the surface of artwork or
transparencies producing continuous tone or screened half-tone file in
black and white, or more usually in separated colours.
> A process by which original art is translated into digital information that
can be manipulated and output via computer. See also flatbed scanner
and drum scanner.
> To partially cut with a rule or wheel heavy paper or board to
SCREEN PROCESS PRINTING
> A method of printing, which forces the ink through a stencil supported
by a fine mesh fabric or metal screen.
> The angles used to offset the different films in process colour
separations. Proper screen angles are critical to minimise moiré
> The number of lines of dots per inch on a halftone.
> The number of lines of dots per inch on a traditional halftone screen.
> (Small computer systems interface) Method of attaching devices such
as hard disks and scanners to the Mac.
> A folded sheet of paper which will make up part of a book or booklet.
Books are usually printed in 4, 8, 16, 32 and 64 page sections.
> A cover of the same material as the inside sheets.
> A set of films in which each piece contains the image information for
one printing plate.
> The marking of a sheet by the transfer of ink from the sheet lying next
to it, can be avoided by the use of anti set-off spray.
> The darkest (black and nearly black) colours or levels of gray in
> The use of software to analyse and sharpen pixel values and alter the
contrast and brightness levels of adjacent pixels to create a perception
of increased sharpness.
> Printing on one side of a sheet from one plate or set of plates and
printing on reverse with another plate.
> A printing press that used precut sheets of paper rather than a
> The direction of the paper fibres along the short edge of the sheet.
> To secure sheets by wire stitching from front to back to the margin.
> A folded section of a book to become part of a publication. Signatures
always contain pages in increments of four, such as 4, 8, 12, 16, 24
or 32 pages.
> A complete line of type cast in one piece.
> An undesirable printing condition where the printed image is smeared.
Slur can result from insufficient blanket pressure, slippage of a press or
lack of ink tack.
> Presses below A2 in size – usually A3 or A4.
> A halftone dot that exhibits a fringe or halo when viewed through a
loupe, often caused by low-resolution imagesetting. This interferes with
density readings and distorts the appearance of gradations.
> The depiction of a digital image on a computer monitor for checking
> Any non-standard colour (for instance gold or silver) used on a 5 or 6
colour press in addition to the 4 process colours.
> The cost of unprofitable materials and labour which cannot be charged
to a specific customer.
> Applying a spot of glue to attach one piece of material lightly to another,
so that it can easily be detached by the recipient.
> Colour printed with a custom ink, rather than with a process
> A varnish applied only to parts of a page, usually to emphasise
> Program with financial and numerical uses.
> To stitch gathered work with wire at the binding edge.
> As for side stitch but using two wire staples, one from either side.
> Hundreds of CCD pixels are organised in columns and rows in a static
array. The number of pixels arrayed defines the true optical resolution of
a CCD-based camera or scanner.
> A duplicate printing plate made in plastic, rubber or metal from a mould
taken from an original plate or forme.
> To sew or staple together with thread or wire the sections of a book
> An alternative to conventional screening that separates an image into
very fine, randomly placed microdots, rather than a grid of geometrically
aligned halftone cells. A method of creating digital halftones in which
photo-realistic images are created using uniformly sized dots distributed
in various densities. Stochastic screening eliminates moiré patterns,
allows greater detail reproduction and ink densities, and is an essential
component of HiFi Colour printing. Also called frequency-modulated
> The paper or other material onto which an image is printed.
> The cyan, magenta, and yellow pigments used in printing to create
different colours. Unlike the additive primaries, these produce darker
colours when combined.
> A wood-free paper produced by processing wood chips in a solution
of sulphurous acid and one of its base sales – calcium, sodium,
magnesium or ammonia.
> Paper given a smooth glazed surface by passing through highly
polished metal rollers under heavy pressure.
> Abbreviation for the Specifications for Web Offset Publications,
developed in the US as a standard for magazine production, and used
to ensure consistency of colour printing.
> A brand of removable cartridge drive of varying capacities which was
widely used by service bureau etc., not so common lately.
> The collection of 256 colours of the colour look-up table built
into a computer’s operating system, to be used for display on an
> The stickiness of an ink. Tack is the relative measurement of the
cohesion of an ink film which is responsible for its resistance to splitting
between two rapidly separating surfaces.
> Colour printing by means of three primary colours (yellow,magenta,
cyan), superimposed; the colours having been separated by electronic
scanning or photographically using colour filters. Four colour printing
with the addition of black is more common.
> Small marks printed at the edge of the image area to enable accurate
trimming of the finished sheet.
> Adding to the artwork or film one of the many patterns or mechanical
tints now available.
> (Tagged image file format) A File format for exchanging bitmapped
images between applications.
THERMAL DYE SUBLIMATION
> Also called thermal dye diffusion transfer, or D2T2. Digital proofing
technology that vapourises solid process pigments either a heated print
head or a laser beam and floats them onto a special stock where they
become solid again.
THERMAL WAX PRINTER
> Similar to dye-sublimination printers, thermal wax devices transfer
colours from RGB, CMY or CMYK ribbons containing waxes, which are
warmed and fused onto paper.
> Tonal values midway between the midtone and shadow points (a 75%
black, or level 192 in 24-bit colour).
> A graphic representation of the relationship between input and output
tonal ranges of an image when its contrast or lightness is being
modified. Separate modification of RGB or CMYK tone curves changes
the colour balance.
> The maximum range of tones that is visible in any original image or a
reproduction. See density range and dynamic range.
> An additional printing plate that adds a matched colour to a process
TOYO COLOUR MATCHING SYSTEM
> A colour matching system that consists of more than 1000 colours
based on the most common printing inks used in Japan.
> A full colour photographic positive for viewing by transmitted light.
> Instrument used to measure the amount of light that passes through an
image on film.
> The preparations of film separations so that adjoining colours
overlap slightly to avoid gaps between colours in the case of slight
misregistration on press. A Pre-press technique which allows for
variations in registration during the press run by spreading or/and
> The actions of wet ink printed on top of wet ink in process colour
> The finished size of a printed piece.
> The area or amount of paper removed by cutting to the tick marks.
> A type of printing in which grayscales are reproduced using three
ink colours, in order to achieve a greater tonal range or produce a
TRUMATCH COLOUR MATCHING SYSTEM
> A colour matching system which provides predictable CMYK colour
matching with more than 2000 achievable computer generated colours.
Trumatch colours cover the visible spectrum of the CMYK gamut in
even steps. The Trumatch colourfinder displays up to 40 tints and
shades of each hue. TruMatch colours are organised according to hue,
saturation and brightness.
> Paper produced from two webs joined together while still wet.
> The distance from the foot of a type character to the printing surface.
The Anglo-American standard being 23.317mm.
> A printing machine which prints one side of the sheet in two colours as
it passed through the machine.
> (Undercolour removal) The removal of CMY percentages that make
up a gray element within darker colours and replacing them with an
appropriate amount of black.
> Paper that has not had a final coating applied for smoothness.
Uncoated paper is absorbent and soft in appearance.
> Paper or card placed under the mounting base of a printing plate to
bring the plate up to type height.
> A name for capital letters (Caps).
> A printing frame in which the negative is held in close contact
with either a sheet of film, photographic paper or a coated plate
> A measure of the lightness or darkness of a hue. The less white in a
colour, the greater its value.
> A transparent coating added to printed material to enhance colour or
> To apply oil, synthetic, spirit, cellulose or water based varnish to
> A half-tone with the background gradually fading away and blending
into the surface of the paper.
> Thickness or thinness of a fluid as measured by its resistance to flow.
Ink viscosity is adjusted to maintain a proper flow through the ink train
of a press and on to the paper.
> That portion of the electromagnetic spectrum to which the human eye
> Paper is wound onto a roll or ‘web’ at the final process in the
manufacturing of paper.
> Web or reel-fed offset litho
printing, offset litho printing is where the
web, or reel is driven directly into the printing machine. The process
lends itself to longer print runs than sheet fed litho printing.
> A printing press that uses paper in webs (rolls), rather than sheets. Web
presses generally work at higher speeds than sheet-fed presses and
may include in-line folding and other finishing equipment.
> Paper made from chemical wood pulp and containing no mechanical
CHEMICAL WOOD PULP
> (Sulphite or sulphate) – pulp
prepared from chipped wood which is treated with chemicals to remove
non-cellulose material; used in better grades of wood pulp papers.
WORK AND TUMBLE
> When a sheet is printed on one side and turned over on its shorter
length and printed on the reverse by gripping on the other long edge.
WORK AND TURN
> When a job is printed in its entirety on first one side then the other
side of sheet by using the same gripper edge. The sheet would then
be split to produce two (or more)of the same job from that sheet. The
advantage of this kind of working is the saving in plate changes.
> A thin, one-piece letterpress printing plate wrapped around the press
cylinder. Similar in appearance to a litho plate.
> Pronunciation WIZ-E-WIG, means What You See I What You Get,
literally that you see on the screen what will be produced by the