Common Printing Terms

If you’ve ever wondered what ‘dot gain’ or ‘trapping’ is, or questioned the difference between ‘leaves’ and ‘pages’ then this section is for you. It contains plain English explanations for the most common printing terms you may hear. Just click on the relevant letter of the alphabet below to find the term you are looking for. If you can’t find the term you want, send us an email about what you want to know and we will answer your question straight away.

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

A
Adhesive binding - A method of binding in which glue is used to hold the leaves in position at the spine.
Adobe Photoshop - A software package used for manipulating images and photographs.
Art Paper - Paper that is evenly coated with a fine clay compound that creates a hard smooth (matt or gloss) surface on one or both sides.
Artwork - Any material or image prepared for graphic reproduction.

 

B
B2 - An ISO paper sheet size - 500mm x 707mm.
B3 - An ISO paper sheet size - 353mm x 500mm.
Background colour     - An area of colour behind text or images.
Backing up - Printing the second side of a printed sheet.
Basic size - A standard size of paper stock (the required size may be smaller or larger).
Bindery - The area of the workplace where print is cut, folded, collated, or bound.
Binding - Fastening together assembled sheets or signatures along one edge.
Bitmap - A digital image of pixels displayed by reference to an array of stored values denoting the colour and tone value of every pixel in the image. Higher resolution images contain more pixels (also referred to as raster graphics).
Blade coating - A paper coating method that achieves a very smooth surface.
Blanket - A fabric coated with a rubber or synthetic compound that is wrapped around the blanket cylinder on a press and transfers the ink from the press plate to the paper.
Bleed - The allowance on a drawing or printing plate that extends the plate beyond the trimmed and finished size, to ensure a clean cut off (usually 3mm).  A printed image (graphic) that extends beyond the trim edge of the paper.
Blind embossing - A technique where a pattern is embossed into the surface of unprinted paper to create an image or text.
Board - The term given to papers of 200 gsm or heavier.
Brochure - A pamphlet bound in booklet form.
Bulk - The thickness of paper relative to its weight. The number of pages per inch of a book relative to its given basis weight.
Burst Binding - Performed by removing a small slot from the spine of the text at folding stage for the adhesive to flow into, allowing the sections to be glued into the cover.

C
CMYK - Cyan, magenta, yellow and black. The four (subtractive) process colours that are used in four-colour printed reproduction.
Coated art paper - Paper for print requiring a special treatment of detail and shading.
Collate - To gather sheets, signatures or page sections of a publication together, ensuring they are complete and in their correct order.
Colour bars - A colour test strip printed on the waste portion of a press sheet.  It is a standardised GATF (Graphic Arts Technical Foundation) process that allows the quality of the printed material relative to ink density, registration and dot gain to be determined.  It also includes the Star Target, which is a similar system designed to detect inking problems.
Colour density - The greater the density or weight of ink the darker the colour appears.
Colour profile - Computer generated information about the printing specification which is used to set up the printing press prior to printing.
Colour proofing - A colour proof is a visual indication that colour separations will produce the required results.
Colour separating - The process of separating the primary colour components for printing.
Colour strength - The relative amount of pigmentation in an ink.
Colour transparency - Transparent film containing a positive photographic colour image.
Colour work - Printing more than one colour on a sheet, usually four colours.
Comb binding - A method of binding individual pages together using a plastic comb.
Computer to plate (CTP) - A process whereby the image is transferred directly from the computer to the printing plate, avoiding the production of film.
Conceptual designs - Initial, rough designs to show how an idea or 'concept' might work. They are usually hand drawn.
Copy - Any material supplied by the customer - artwork, typescript, photographs, drawings - to be used in the production of printed material.
Cover - A term describing a general type of paper used for the covers of books, pamphlets, etc.
Creasing - A method of enabling thicker materials to be folded without cracking.
Creep - In a saddle stitched booklet the bulk of the paper causes the inner pages to extend further out than the outer pages when folded. When trimmed the inner pages are narrower than the outer pages. We have software to counter this.
Crop marks - Marks on each corner of a sheet indicating where the sheet will be guillotined to the finished size.
Cutting - See guillotining.
Cutting out - The method of cutting paper or board to irregular shapes using a cutting forme and platen. Widely used in producing folders.
Cyan - A shade of blue used in the four-colour process. It reflects blue and green and absorbs red.

D
Dampening - An essential part of the printing process whereby cloth covered rubber rollers distributes the dampening solution to the plate.
Densitometer - A sensitive photoelectric (optical) device used by printers and photographers to measure and control the density of ink colours (reflection densitometer), as well as check reproduction dot sizes in order to maintain quality assurance in colour (transmission densitometer).
Density - The lay of paper fibres relative to tightness or looseness that affects the bulk, absorbency and finish of the paper. Also, the degree of tone, darkness or colour within a photo or reproduction that is measurable by a densitometer.
Design - The interpretation of an idea as a layout on paper. Often referred to as the initial draft of a brochure, leaflet or poster before the text and images have been finalised.
Digital - In printing, a term that covers digital printing from a computer file without the use of conventional inks and plates. Digital also refers to digital proofs which have been produced without film.
Digital file - An art file that resides on disk, usually in a native application format.
Digital Proof - Proofing using our digital printing press. Useful for brochure mockups on near job stock.
Dimensional stability - The ability of paper to maintain its original size when under pressure, or exposed to moisture.
Distribution  - The means of delivery of the finished job to one or more locations.
Dot  - The smallest individual element of a halftone. Its size (density) is related to the density of the original used to produce it, indicated by the percentage of the area it occupies from zero to one hundred percent.  It may be circular, square or elliptical.
Dot gain - An increase in the size of a halftone dot - as it is transferred from film to plate, from plate to blanket and from blanket to paper that may occur as a result of errors or imperfections in any of the steps between screening an image and printing it onto paper.
Drying - The process of allowing the printed sheet to dry before finishing the sheet.
DTP - Desktop Publishing - combines a personal computer and WYSIWYG page layout software to create publication documents on a computer for either large scale publishing or small scale local multifunction peripheral output and distribution.

E
Electronic scanning - The scanning of an original by a light-sensitive cell that transmits electrical impulses to a light beam in ratio to the density of the original.
Embossing - A technique to raise the surface of an image or text to make it stand out from the page.
Encapsulated PostScript (EPS) - An image description format. EPS translates graphics and text into descriptions that can be used by the printer. The font and pictures themselves are encapsulated into the EPS code.

F
Finishing - Finishing embraces all of the steps of the production process after ink has been applied to the sheet.
Finishing techniques - The term applied to laminating, embossing, UV varnishing, cutting out etc. which are used to enhance the finish of the job.
Fold, Stitch & Trim (FST) - Folding printed sections which are then collated, stitched and trimmed to the finished size.
Foil blocking - A technique to apply an image to paper or board using metal foil. This technique is normally used for prestigious literature.
Folder - A machine that folds the paper after it has been printed, according to the end size of the publication.
Folding - The process of converting the flat printed sheet into a folded section prior to trimming.
Fold marks - Lines on printed sheets showing where to fold it.
Four-colour process - Colour printing by means of the three primary colours plus black superimposed.
Four-colour process inks - Inks used for four-colour process printing (i.e. yellow, cyan, magenta and black).

G
Gatefold - A fold which turns in on itself from both edges to the centre.
Gathering - To place in correct order sections of a book or leaves of a multi-part set.
Gloss laminating - See laminating.
Grain - The direction in which the fibres of a substrate (paper) lie.
GSM - 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. Standard bond is around 80 GSM.
Guillotining - Flat sheets and untrimmed booklets, brochures and leaflets are trimmed to size with straight cuts using a guillotine cutter.
Gumming - The application of gum arabic to the non-printing areas of a plate.

H
Halftone - The reproduction of continuous tone artwork, such as a photograph through a cross-ruled screen that converts the image into a pattern of dots of various size. The principle relies on the frequency of the dots being fine enough so the viewer at a normal reading distance is unable to distinguish the pattern.
Hard copy - A physical proof which you can touch and feel as an alternative to a PDF or electronic proof which can only be viewed on a computer screen. Hard copy also refers to any item of artwork or text which is supplied on paper rather than as a computer software file.
Hot melt - An adhesive used in the binding process that requires heat for application.
HSB - Hue, Saturation, Brightness. Hue is the pigment, saturation is the amount of pigment, and brightness is the amount of white included. With the HSB model, all colours can be defined by expressing their levels of hue, saturation and brightness in percentages.
Hue - The ability to perceive the main attributes of colours using the human eye.
Hue error - The difference between the printed colour and the colour it is supposed to represent.
Hydrophilic area - The non-image areas of a lithographic plate, which attracts water and repels the oil-based ink.
Hydrophobic area - The image areas of a lithographic plate, which repels water and attracts the oil-based ink.

I
Image area - The portion of the printing plate that carries the ink and prints on paper.
Image manipulation - The technique of using computer software to alter or improve an image. Often used to remove blemishes or unwanted artifacts from photographs.
Image resolution - The fineness or coarseness of digitised image, in dots per inch (DPI).
Imagesetter - An imaging device for creating type and graphics, using either raster or vector techniques to expose film.
Impose - To plan films of pages etc. into correct position prior to plate making.
Imposition - The correct sequential arrangement of pages to be printed, with all margins in proper alignment, for printing plate production.
Imposition schemes - Plans for the arrangement of the pages of a book so that they will follow in correct sequence when folded.
Ink - Liquid containing pigments which is applied to paper or board in the printing process.
Ink ducts - The nozzle through which the ink passes before it is transferred to the unprinted sheet.
Insert - Unsecured paper or card inserted between the leaves of a book or brochure. Also, a piece of printed material prepared for insertion into a publication.
ISO - International Standards Organisation.

J
JPEG - Joint Photographic Experts Group. A highly compressed graphics format designed to handle computer images of high-resolution photographs as efficiently as possible.

K
Keyline - Black lines drawn on artwork indicating the exact placement, shape and size of elements including halftones, illustrations, etc.
Knife fold - A fold created by a blunt straight edge plunging down into the middle of a flat sheet.

L
Laminated - See laminating.
Laminating - The process of applying a plastic film to a printed sheet to enhance and protect it. Laminates are available in matt and gloss finishes.
Layout - A sketch of printed work, showing the proposed position of all the elements, roughs, thumbnails etc. of the final printed piece before it goes to print.
Leaflet - A single or double sided sheet, usually containing information. A sheet can also be folded to make a four sided leaflet.
Line copy - (Line work) Any copy or artwork that has no gradations of tone and can be reproduced without the use of halftone screens.
Litho - See lithography.
Lithography - A printing process in which the paper makes contact with the whole surface of the plate but the image areas of the surface are treated to receive and transmit ink to the paper.  The non-image areas are treated with water, which rejects the ink from the ink roller.
LPI - Lines Per Inch.  A measure of resolution for halftones.
Loop wire stitching - Similar to a conventional wire stitch (staple) but with a loop which allows the brochure to be contained in a ring binder without drilling holes in the brochure.

M
Machine coated - Paper coated during the papermaking process.
Machine or mill finished - Paper finished on the machine, but not supercalendered.
Machine varnish - A varnish applied to the sheet on press. Often used to seal heavy solid inks.
Magazine - A periodical publication containing pictures, stories and articles of interest for the reader.
Magenta - One of the subtractive primaries, the hue of which is used for one of the four-colour process inks.
Make ready - The operations involved in preparing a printing machine for run.
Make up - The assembly of text, headings and illustrative material into pages with headlines, folios, columns, etc. (traditionally a manual operation) now performed electronically.
Matt laminating - A matt finish used to enhance and protect a printed sheet. See laminating.
Mechanical paper - (Part mechanical)  Any paper containing mechanical wood pulp.
Mechanical wood pulp - Produced by grinding wood mechanically and used in cheap papers such as newsprint.
Metallic inks - Ink which contains metallic particles to create a metallic effect when applied to the sheet.
Mono - Single colour (black) printing.
Monochrome - An original in one colour only.

N
Negative - Film containing an image in which the colour values of the original are reversed.
Newsletter - A publication, usually from an organisation, providing information about the organisation and its activities to its employees, customers and other interested parties.
Newsprint - A light, low cost, lower quality, absorbent paper, made from mechanical pulp.

O
Offset printing - A lithographic method of printing in which the ink is first transferred (offset) from the plate to a blanket and then transferred to the paper or board.  The most commonly used printing method.
Optimised - When a computer file is adjusted to improve its suitability for printing.
Overprinted - A term which describes when a colour is printed on top of another, usually it refers to dark text which is printed on top of another, lighter colour. It can also refer to text which is printed onto a previously printed flat sheet and is a technique which is often applied to multiple language versions of literature and to price lists.
Overs - The quantity of a printed job produced above that which was ordered.

P
Page makeup - The assembly of all the elements that make up a page.
Pagination - Numeric page ordering split between right and left facing pages.
Pantone - An international trademark palette for colour standards from Pantone Inc.
Pantone colours - A colour system of over 1200 standard colours developed by Pantone Inc.
Paper - The term given to ‘papers’ of less than 200gsm. Papers of over 200gsm are referred to as ‘boards’.
Part mechanical paper - Paper made from a combination of chemical and mechanical wood pulp often having a creamy appearance.
PDF - Portable Document Format – file created from artwork for use in proofing through to producing plates for printing.
Perfecting - Printing both sides of a sheet in one pass through the machine, or printing the second side of a sheet - backing-up.
Perfect binding - A term used to describe a binding process in which the signatures of a book are held together by a flexible adhesive.
Perfecting press - A printing press that prints on both sides of the page in a single pass.
Perforated - A row of small incisions pressed into the paper surface to enable the paper to be torn accurately along the line of the perforation. Often used for tear off reply cards.
Photo retouching - Treatment of a photograph to remove dust spots or blemishes, or to adjust or remove unwanted elements of the image, or add new elements to an image.
PhotoShop - A software program created by Adobe Systems Inc. for the manipulation of scanned images for PostScript output. Available for Apple Macintosh and Windows platforms.
Plate - The metal (usually aluminium) plate that carries the printing image on a lithographic press.
Plate cylinder - The cylindrical surface on a rotary printing press that carries the plate.
Positive - A film or print that contains an image containing the same tonal values as the original.
PostScript - A page definition language (PDL) developed by Adobe Systems.  A page of text and/or graphics saved as a PostScript file is stored as a set of instructions specifying the measurements, typefaces, and graphic shapes that makeup the page.
PPD file - PostScript Printer Description file.  A file that contains screen angle, resolution, page size and device-specific information for a file to be printed on a PostScript device.
PPI - Pixels per inch.
Prepress - The preparation work required to turn camera-ready artwork into the printing plates needed for mass production (e.g. scanning, stripping and colour separating).
Press check - The final check when a job is already on the press, or examining first printed sheets.
Primary colours - In printing - yellow, magenta and cyan (subtractive primaries).  In light - red, green and blue (additive primaries).
Process colours - The subtractive primary colours cyan, magenta, yellow and black.
Process colour printing - The recreation of colour by combining two or more of the subtractive colours cyan, magenta, and yellow and black.  Printing from two or more plates containing halftones representing process colours to produce intermediate colours, shades and tones.
Process plates - A set of printing plates using halftones to produce a variety of colours and shades - usually three or four-colour process.
Production layouts - A page layout which is prepared from the proposed content to ensure that the content fits on to the page within the constraints of the agreed page design format.
Progressive proof - A set of proofs made from the separate plates showing each colour individually and in register.
Proof - A copy of any work in progress, usually for checking and correcting.
Pulp - The raw material for papermaking.  Mainly fibres from wood, paper and rags.

Q
Quality control - The process of taking random samples during the press run to check the consistency of quality.

R
Reflection copy - An illustration, copy or photograph viewed and reproduced by reflecting light from its surface.
Reel - The master roll of paper as it comes off the papermaking machine, which is then cut into smaller rolls.
Register - The arrangement of two or more images in exact alignment with each other.
Registration marks - Any cross marks or other symbols used on a layout to assure proper registration.
Registration - The quality of alignment of the coloured inks when applied to paper.
Reprographics - (Repro) The process of producing four-colour separations from artwork for plate production.
Retouching - Treating artwork or film to make corrections or modify tonal values.  The correction or deliberate manipulation of colour, tone or detail in an original work of art, photograph, etc.
Reversed out - Light coloured (or white) text which appears on a darker background is described as being reversed out of the background.
Ring binder - A binder which contains metal 'rings' which can be opened to insert predrilled paper. When closed, the paper is held in place. Ring binders are ideal for large documents or for documents where the content needs to be revised on a regular basis.
RIP - Raster Image Processor.  The hardware/software that converts data stored in a computer as a series of lines of tiny dots, for output to film or photographic paper. 
Rolling power - The amount of pressure a press can apply to achieve a high quality solid colour over a large area. A bigger press has more rolling power than a smaller press and usually achieves a higher quality result.
Rubbing - Rubbing occurs where a sheet with heavy dark solid comes into contact with an unprinted sheet and leaves an ink deposit on it.
Run on - The quantity of printed copies above the original amount required.

S
Saddle stitching - (Saddle wire or wire stitching).  Binding printed materials with wire by stapling the pages on the folded spine to produce a booklet.
Scan - To convert images into files (usually TIFF) for placing into artwork for printing.
Scanned - See Scan.
Scanner - An electronic device that scans across the surface of artwork or transparencies producing continuous tone or screened halftone film in monochrome, or separated colours.
Sealer varnish - See machine varnish.
Sealing - A clear substance applied (usually to a silk or matt sheet) to aid drying and prevent rubbing and marking.
Section - A folded sheet of paper that will make up part of a book or booklet, usually printed in 4, 8, 16, 32 and 64 page sections.
Self cover - A cover made from the same paper stock as the inside sheets.
Signature - A printed sheet to be folded.
Software - A computer program used to carry out a given task.
Special colour - Any non-standard colour (for instance gold or silver) used in addition to the four process colours (or instead of).
Spoilage - The cost of unprofitable materials and labour that cannot be charged to a specific client.
Special colours - See spot colour.
Spot colour - Any non-standard colour (for instance gold or silver) used in addition to the four process colours (or instead of).
Spot gluing - Applying a spot of glue to attach one piece of material lightly to another.
Spot varnishing - Varnish is only applied to specific areas on the sheet such as a picture or a text headline to make it stand out.
SRA2 - An ISO paper sheet size - 450mm x 640mm.
SRA3 - An ISO paper sheet size - 320mm x 450mm.
Staggered folding - Where a sheet is folded so that one page overlaps another page to allow information from several pages to be seen together.
Substrate - Paper, card, metal - any material onto which an image is to be printed.
Supercalandered - Paper given a smooth glazed surface by passing it through highly polished metal rollers under heavy pressure.
Super calendaring - A machine procedure that produces a high finished paper surface that is extremely smooth and exceptional for printing.

T
Tabloid - The page size of newspaper that is half the size of a broadsheet.
Three-knife trimmer - Three guillotines that trim the top, bottom and side of a book in one pass.
Tick marks - Small marks printed at the edge of the image area to enable accurate trimming of a finished sheet.
Transparency - A clear, continuous tone original used for colour photographic images. 
Transparent - Inks that do not block out the coloured inks that they print over, but instead blend with them to create intermediate colours.
Transparent copy - Illustrative copy such as a colour transparency, through which light must pass in order for it to be seen or reproduced.
Trim areas - The area or amount of paper removed by cutting to the tick marks.
Trim marks - Guides that show where a document will be cut to fit the specifications of a final printed product.
Trimming - The process of removing the unwanted edges of the printed sheet to achieve the finished size.

U
Unit - A combination of inking, plate and impression operations required to print a single colour (on multicolour printing presses).  A four-colour press has four printing units.
Up (x Up) - The number of similar sheets that can be produced on a larger sheet (two up, four up, etc.).
UV varnishing - A finishing process where a varnish is applied to the sheet (or certain parts of the sheet) and is then dried using ultra-violet light. Available in gloss and matt finishes. Gloss UV varnish has a very high gloss finish and is often used as a spot varnish with matt laminates to highlight images and text. Matt UV varnish is less popular and is used with gloss laminates to create special effects.
UV gloss varnishing - See UV varnishing.
UV matt varnishing - See UV varnishing.

V
Varnish - The primary component of the ink vehicle. 
Varnishing - The application of oil, synthetic, spirit cellulose, or water based varnish to printed material (often dried via an ultra violet radiation process) to enhance appearance.
Vehicle - A combination of varnish, waxes, dryers, etc. that contains the pigment of inks and controls the flow, the drying and the adhesion of the pigments to the printed surface.

W
Web - A continuous reel of paper used in web or rotary printing.
Web offset - A lithographic method of printing where the ink is transferred from the image to an offset blanket and then to both sides of the paper, which runs from continuous reels or webs.  Used to print longer run high pagination material.
Web press - A printing press that prints onto rolls of paper passed through the press in one continuous piece, as opposed to sheets of paper.
Wire Stitching - See saddle stitching.
Wiro binding - A method of binding individual pages together using a shaped wire which is inserted into punched holes and then crimped shut.
Wood-free paper - Paper made from chemical wood pulp (cellulose) and containing no mechanical wood pulp (lignin).
Wove paper - Finely textured paper with no visible wire marks.
Wove - A smooth paper made on finely textured wire that gives it a gentle patterned finish.

Y
Yellow - One of the subtractive primaries, the hue of which is used for one of the four colour process inks. It reflects red and green light and absorbs blue light.