Glossary of terms
Adhesive binding
(see also Perfect Binding & PUR Binding) Type of thread-less binding in which the leaves of a book are held together at the binding edge by glue or synthetic adhesive.
Against the Grain
Folding at right angles to the grain direction of the paper being used, as opposed to with the grain. Also called across the grain and cross-grain. This can cause cracking on heavier papers unless the paper is scored or creased
Author’s Corrections
Corrections made by the author on proofs,that alter the original copy. Author’s corrections are chargeable at the discretion of the printer.
Back Up
Printing on the reverse side of a sheet already printed on one side. Back up position is critical and must be accurate to ensure consistent position throughout a folded product.
Black and White
Originals or reproductions in single colour, also known as monotone or mono.
Blade coated
Paper coated by a process in which the freshly applied wet coating is smoothed and the excess removed by a thin, flexible metal blade which bears on the coated surface.
Blanket
In offset printing, a rubber surfaced fabric that is clamped around a plate cylinder to transfer the image from the impression cylinder to the substrate.
Bleed
When the printed image extends beyond the trimmed area of a page, the image must be increased, usually by a minimum of 3mm. This extended area isknown as the bleed.
Blind Embossing
The process of stamping an image into the paper to produce a depressed effect on the paper surface, without the use of inks.
Blind Blocked
In binding, to impress or stamp a design upon the cover. The design can be blocked in coloured inks, or metal foil, including special effects such as holographic.
Bond Paper
A grade of writing or printing paper, usually used for letterheads or business forms.
BPOP
Abbreviation for “Bulk packed onto pallets”.
Broadsheet
Any sheet in its basic size (not folded or cut); also denotes a newspaperformat.
Bulk
Thickness of a sheet of paper or board. Also used to indicate the relativethickness of a sheet in relation to its weight. Usually measured in microns (1,000th of a millimetre) ot 1,000 of in inch.
Case
In bookbinding, the hard covers of a case bound book
CMYK
Cyan, Magenta, Yellow, Key (black), being the primary colours used as the basis for 4-colour process printing. Also known as 4 colour process.
Coated Stock
Material coated on one or both sides with a mixture china clay, latex and other loadings to fill up surface pits and improve the printing surface. The process can be accomplished either on-line on the papermaking machine (machine coated) or as a separate operation (off-machine coated).
Colour Correction
Alteration of the colour of a photographic image by electronic retouching.
Colour Proofing
This term describes a wide range of techniques which have been developed to reproduce full colour images from film or digital data available, prior to the actual print run; thus allowing the client, colour separation house and printer to view the “proofed” result, prior to the actual print run.
Colour Separation
In photographic reproduction, the process of separating colour originals into the primary printing colour components.
Concertina Fold
Folding each panel of a leaflet in alternate directions, so that when opened out the finished product is folded in a zigzag fashion.
Contrast
The tonal gradation between the highlights, middle tone and shadows in an original or reproduction.
Crease
An indented line pressed into the substrate to reduce resistance and allow folding without cracking or splitting.
Crop
To cut a piece of copy or artwork to the size indicated on an original by cropmarks.
Crossover
When an image runs across two pages, requiring the image to be split where it crosses the spine.
CTP
Acronym for Computer To Plate, the process by which digital data is converted via a RIP device to drive a platesetter, which generates the finished printing plate.
Densitometer
A device for measuring the colour density at a specific location on film or printed product, either by reflected or transmitted light.
Descender
That part of a lower case letter which extends below the main body as in the letter g.
Die-Cutting
The process of using sharp steel blades known as rules to cut a shape into paper or board.
Die-stamping
An intaglio process of printing in which the resultant impressionstands out in relief above the surface of the stamped material, either coloured (using inks or foil) or blind (no inks or foils).
Digital Colour Proofs
A colour proof produced from digitaldata. Digital proofs may be Pre-RIP (before rendering pixels), or Post-RIP. Low resolution proofs are generally used to check content only and High resolution to check colour matching.
Dot
The individual element in both halftones and four colour process printing.
Dot Gain
In printing, a defect in which dots print larger than they should, causing darker tones and stronger colours.
Dots Per Inch
(dpi) A measure of resolution on the printed page.
Drawn-on Cover
A paper book cover, which is attached to the sewn book by gluing the spine.
Drop-Out
Fine halftone dots or fine lines which are eliminated from thehighlight areas of the plate during the platemaking process.
Duotone
A two-colour halftone reproduction from a one colour photograph.
Dummy
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.
Embossing
The process of impressing an image in relief into the paper to produce a raised effect on the paper surface, without the use of inks.
EPS
Encapsulated Post Script, a computer file format usually used totransfer post script information from one program to another.
Filmsetter
An output device which produces film positives or negatives directly from Ripped data.
Fit
Printers’ terminology for the accurate positioning of all of the elements of one colour with all of the elements of another colour on a printed sheet. Sheets may "register" but not fit.
Flexography
A relief process in which printing is done from a rubber or plastic stereo (plate). Flexo presses can print on a wide variety of substrates including metal and plastic, but print quality is inferior to litho or gravure.
Flying Imprinter
A device on a printing unit of a web press which allows for one plate to be changed without stopping the machine.
Folio
The page number.
Forme
In printing, one side of assembled pages or other images for printing. In die-cutting, the wooden board in which the cutting, creasing and perforating rules are mounted.
Four-colour Process
Technique of printing that uses black,magenta, cyan and yellow to simulate full-colour images. Colours are reproduced by combinations of these four process colours. Also called process printing.
FPO
An acronym (For Position Only) used in mechanical presentation toidentify the crop specifications on a specific piece of composition.
Galley Proof
A proof of text before being made up into pages. Also known as a slip proof.
Ganging-up
Imposing different images on a sheet to save makereadies. Different ratios of images can be used to create different quantities; for instance a sheet 8 images can be printed 4 3 1, so each 1,000 printed sheets would contain 4,000 of image one, 3,000 of image two and 1,000 of image three.
Gilding
In book printing, the application of gold leaf to the edges of a book.
Grain
In papermaking, the direction in which most of thefibres run. Tear any piece of paper and it will have one direction where it tears in a straight line (the grain direction) and one where the tear is more ragged (across the grain). Wetting a strip paper will cause it to curl in the opposite direction to the grain.
Grey Balance
The combination of the four process colours which produce a neutral grey.
Grind-Off
The area which runs along the spine of each section (signature) of a perfect bound book which is removed after being gathered to allow the glue to penetrate every leaf. The UK standard grind-off dimension is 3mm.
GSM
Abbreviation of grams per square metre. Denotes the substance of paper or board – the higher the gsm, the heavier the substrate.
Gutter
The blank space or inner margin from printing area to binding.
Halftone
The reproduction of continuous-tone artwork into a series of dots.
Impression
In printing, the pressure of the plate or blanket as it comes incontact with paper.
Imposition
Arrangement of pages in a sequence, which will read consecutively when the printed sheet is folded.
Jog
To align sheets of paper into a pile prior to cutting.
Kerning
In typesetting, the spacing between two characters.
Keyline
An outline drawing on artwork to indicate the exact shape, position and size for such elements as halftones, line sketches, etc.
Kiss-Cut
Light cut into the peelable surface of a selfadhesive sheet, leaving the backing sheet intact.
Laid
Finish on bond or text paper on which grids of parallel lines simulate the surface of handmade paper. Laid lines are close together and run against the grain; chain lines are farther apart and run with the grain.
Lamination
A plastic film bonded by heat and pressure to a printed sheet. The laminate can be either gloss or matt to enhance the appearance of the print and provide moisture-resistant protection to the paper surface.
Landscape
Orientation of the sheet or end-product where the horizontal dimension is greater than the vertical.
Leading
In composition, the distance between lines of type, measured in points.
Letterpress
Method of printing from raised surfaces, either metal type or plates whose surfaces have been etched away from image areas. Also called block printing.
Line Copy
Copy suitable for reproduction without using a halftone screen.
Lithographic printing
Method of printing using plates whose image areas attract ink and whose non-image areas repel ink. Non-image areas may be coated with water to repel the oily ink or may have a surface, such as silicon, that repels ink. The printing and non printing surfaces are on the same plane on the plate and the substrate makes contact with the whole surface.
Long grain press
A press where the longest side of the standard folded product runs parallel to the grain of the paper.
Loose Insert
Any item inserted into a printed product without being affixed in any way. Can be either placed (in a specific position in the product) or random (anywhere in the product).
Make-Ready
In printing, all work done to set up a press for printing, beforeimpression count is activated and good copies are produced.
Mask
In colour separation photography, an intermediate photographic negative or positive used in colour correction.
Mechanical
A term for a camera-ready paste-up of artwork.
Machine finished(MF)
Any finish obtained on a papermakingmachine. It can refer to either the finish on the sheet as it leaves the last drying cylinder of the machine, or the finish given to a sheet by calendering online.
Mid Tones
The tonal range between highlights and shadows of a photograph orreproduction.
Moiré
Screen pattern caused by a clash of screen angles in litho reproduction.
Offset
In printing, the process of using an intermediate blanket cylinder to transfer an image from the impression cylinder to the substrate.
Overprinting
Printing onto a sheet which has been previously printed. Typically used to add dealer addresses to generic brochures.
Pantone
The Pantone Matching System (PMS) is a colour standard which defines a wide range of colour solids and the combination of process colours required to achieve the closest match to the solid Pantone colour.
Part Mechanical
A paper containing up to 50% mechanical pulp, with the remainder being made up of chemical pulp.
Perfect Binding
A method of adhesive binding with a square-backed spine. Individual sections are collected together and the spine is ground off. Hot-melt glue is then applied to the spine and a cover drawn on before the product is trimmed flush to the final size.
Perfecting Press
A printing press that prints both sidesof the sheet in one pass through the press.
Pixel
In electronic imaging, the basic unit of digital imaging.
Plate Cylinder
The cylinder of a press onto which the printing plate is mounted.
Platesetter
An output device which produces a finished printing plate directly from Ripped data. Also known as a CTP device.
Portrait
Orientation of a sheet or end-product where the vertical dimension is greater than the horizontal.
PostScript
A page description language (PDL) developed by Adobe, which defines the contents and layout of a page in electronic form. PostScript is also programming language which is interpreted by a PostScript RIP in output devices such as filmsetters or platesetters (CTP) in order to reproduce the original page.
Pre-Press
The stage of the print production process which takes place afterdesign and before printing.
Primary Colours
Additive and subtractive primary colours can be mixed to form all other colours. The additive primary colours are red, green and blue (RGB) and can be added together to make all other colours, as is done when light is emitted from the screen of a television set or computer monitor. The subtractive primary colours (cyan, magenta and yellow) are those that, when mixed, subtract light from white to make all the other colours. This is what happens when pigments are mixed to create printing inks.
Process Printing
Printing using the process colour set (CMYK).
Progressive Proofs(Progs)
Proofs which show the sequence ofprinting and the result after each additional colour has been applied.
Proof
A representation of the printed product which is checked prior to print production.
PUR Binding
The same process as perfect binding, but a synthetic adhesive(Polyurethane React) is used in place of conventional hot-melt glue. The glued spine is more pliable and the adhesive bond much stronger than a perfect bound product and so has increased longevity.
Quarter-fold
Two or more folds, each fold at 90 degrees to the previous one. Also called right-angle fold.
Ram Bundled
A method of packing printed products by strapping a bundle very tightly with end-boards to compress the product and keep it flat for subsequent machine insertion.
Ream
Five hundred sheets of paper.
Register
Adjustment of colour plates to obtain perfect super imposition of colours.
Register Marks
Cross-hair lines on mechanicals, films and plates used for positioning pages or images to enable accurate register on press.
RGB
Red, green, blue additive primary colours. RGB files must be converted to CMYK at the pre-press stage prior to printing 4 colour process.
RIP
Acronym for Raster Image Processor, which generates a bitmap to send to the printing device (filmsetter, platesetter or digital press). The input data is either a file written in a page description language such as PDF or another bitmap. In the latter case, the RIP applies either smoothing or interpolation algorithms to the input bitmap to generate the output bitmap.
Saddle-stitch
Method of binding where folded sections are inset and secured together with wire staples (also known as wire-stitch).
Scanner
An electronic device used to convert a continuous tone original into a series of halftone dots for printing.
Serif
The short cross-strokes at the ends of the main strokes of letters in some typefaces. Fonts with these cross-strokes are known as serif faces and those without are known as sans serif.
Short grain press
A press where the shortest side of the finished product runs parallel to the grain of the paper.
Show through
The degree to which a printed image is visible through the paper due to the lack of opacity of the paper.
Spiral Binding
A book bound with wires in spiral form inserted through holes punched along the binding.
Spot varnish
The application of varnish to selective areas to create a highlight or contrast effect.
Stock
The wet pulp before it is fed onto a papermaking machine, or during the papermaking processes before it becomes a sheet of paper; contains around 99% water and 1% fibre. Also the colloquial term for the paper type used in a printed job.
Tolerances
The specification of acceptable variations in a range of printingparameters to take account of the imperfections in each process.
Trapping
To print a wet ink film over previously printed ink. Dry trapping is printing wet ink or varnish over dry ink. Wet trapping is printing wet ink or varnish over previously printed wet ink.
Trim Marks
In printing, marks placed on the copy to indicate where the papershould be trimmed.
Undercut
In printing presses, the difference between the radius of the cylinder bearers and the cylinder body, to allow for plate (or blanket) and packing thickness.
UV Varnish
A liquid coating applied to a printed sheet for protection andenhancement, which is dried immediately by exposure to UV light.
Varnishing
The application of any form of liquid varnish to printed matter in order to enhance its appearance or increase its durability.
Vignette
A design or illustration in which the background fades gradually away to white.
Wire-0 Binding
A continuous double series of wire loops run through punched slots along the binding side of a booklet.
Wire Side
Side of the paper that rests against the manufacturing wires during papermaking. Typically the rougher side of the paper.
Woodfree
Paper with no mechanical wood pulp. Woodfree papers actually contain wood pulp which has been chemically treated to enhance the whiteness of the paper.
Work and Tumble
In sheetfed printing, to print one side of a sheet paper, then turn it over from grip edge to back (leave) edge, using the same plate and sidelay to print the second side but using a different grip edge.
Work and Turn
In sheetfed printing, to print one side of a sheet paper, then turn it over from left to right and print the second side using the same grip and plate but opposite sidelay.