printing terms

Further to our bookbinding terms article last year, we thought we would publish a similar glossary, this time for common printing terms. We have restricted this to commonly occurring, contemporary printing terms i.e. those which are likely to be most useful or interesting to folks outside of the printing industry, avoiding the terms which pertain to historical printing techniques if they are no longer widely used. We have also avoided repetition of most of the bookbinding terms from the earlier post although retain a few which might apply to printing generally too. We hope this list is useful:

A

  • A0: the paper size 841mm x 1189mm (twice A1)
  • A1: the paper size 594mm x 841mm (twice A2)
  • A2: the paper size 420mm x 594mm (twice A3)
  • A3: the paper size 297mm x 420mm (twice A4)
  • A4: the paper size 210mm x 297mm (twice A5)
  • A5: the paper size 148mm x 210mm (twice A6)
  • A6: the paper size 105mm x 148mm
  • American Quarto (a.k.a. ‘Letter’): the paper size 215.9mm x 279.4mm
  • Above the fold: a reference to the part of the document’s front face which is in the upper section first visible to the onlooker. Similarly it refers to the part of a web page first visible without the need to scroll down.
  • Accordian fold: this is where a document is folded with several parallel folds and thereby concertinas closed or opens up like an accordian.
  • Advertorial: essentially an advert in a magazine or publication, disguised as a piece of editorial.
  • Ai files: digital artwork supplied in Adobe Illustrator format.
  • Ampersand: the letter ‘&’ which means ‘and’.
  • Anti-offset spray (a.k.a. set-off spray): a dry application sprayed onto the surface of printed documents so as to reduce or eliminate the chance of ink passing from the face of one printed document to the underside of the next. Used especially when large areas of dense or dark colours are being printed.
  • Art paper (compare to uncoated paper below): a type of ‘coated’ paper which has a fine coating of a clay-based compound (usually white), which is carefully processed so as to form a very smooth, hard, flat surface which takes ink very well without allowing much of it to absorb into the paper fibres (so printed colours look more saturated). Some are gloss coated, some matt, and some silk.
  • Artwork: the graphical files prepared for hand-over to the printer. These days these are often Acrobat PDF files although may also be Adobe InDesign files, EPS files, Quark Express files etc.
  • Ascender: in typography this is the part of the letter which extends above the main body (or ‘X-height’) of the letters. For example the upper ‘tail’ of a lower case b. Compare to descender below.
  • ‘A’ sized papers: the UK’s standard ISO paper sizes, each having a length to width ratio of 1:1.414 (or 1 to the square of 2). See A4, A3 etc. above for individual sizes.
  • Aspect ratio: refers to the proportions of an element (usually a picture or photo) i.e. the ratio of the width to the height.

B

  • Bindery: This is where printed jobs (especially in bookbinding) undergo their final stages. These include any hole drilling, creasing and folding, gluing, stitching, trimming and any packaging.
  • Binding: the process of fastening individual loose pages of a book, brochure or publication together, usually at the spine. The overall process usually includes folding, cutting, collating, stitching and/or gluing.
  • Bleed: is is the extra printed area (usually 3mm) extending off the final trimmed edges of a document. It is added, at artwork and printing stage, to graphical elements and photos which extend to the very edge of the final document. The bleed is added to make sure that no unprinted white margins show if the final trimming is not accurate to the millimetre.
  • Blind embossing: an image formed, usually in paper, card or leather, purely by forcing a shaped metal ‘stamp’ into the material via pressure and without any ink or pigment of any kind. The result is a colourless bas relief effect.
  • Buckram: traditionally a cotton or linen cloth, or a mixture of both, which has been stiffened using gum or paste during manufacture. More recently it has also been manufactured using acrylic so as to be waterproof and super-tough, however this also usually features the traditional linen texture. Buckram book cloth is used in bookbinding to cover the outside of the book. More details can be found in our Bookbinding Common Terms blog post.
  • B&W: black and white (abbreviation).

C

  • Case: the hard exterior cover of a hardbound book.
  • Case binding: bookbinding which uses a hard cover (or ‘case’).
  • CMYK: refers to the 4 ‘process’ printing colours of Cyan, Magenta, Yellow and blacK (K is used for black to stop any confusion – B might be confused with blue).
  • Coated paper or stock: see ‘Art’ paper.
  • Colour bars: the series of different colours printed usually in a strip outside the actual document area (later trimmed off). These help the printer optimise things like ink weight/density and to control dot gain and registration during the printing process.
  • Comp (short for composite): an initial design visual, mock-up or sketch.
  • Crop marks: printers marks which show the printer where to cut the printed sheet. They normally sit outside the document area by a few millimetres so are cut off so as not to show on the final printed document.
  • Cutter (or cutting die): often used for printed jobs which are not square or rectangular, i.e. are a unique shape, cutters usually consist of a backing board of ply with shaped blades embedded in it. This is pressed into the printed sheets to press out the shape.
  • Cyan (or C): is the sky blue ink used in 4 colour ‘process printing’. It is the C in ‘CMYK’.

D

  • Debossing: the recessed shape or image made when a letterpress style die is forced against the surface of the paper, board or cover under pressure.
  • Deckled edge: the rough, feathery edge of paper sheets which have not been trimmed with a guillotine.
  • Descender: in typography this is the part of the letter which extends below the main body (or ‘X-height’) of the letters. For example the lower ‘tail’ of a lower case y. Compare to ascender above.
  • Die: metal blocks which have a design of some kind (shape and/or lettering) cut into it. This is then used to stamp the design (including foil or embossing/debossing) onto the paper, board or cover.
  • Die cutting: the process of cutting a (usually) non-regular shape using a Cutting Die (see ‘Cutter’ above).
  • Die stamping: the process of stamping a design onto paper or board using a metal die (see ‘Die’ above). The result can be foil or colour blocking, embossing or debossing.
  • Digital Printing: is a modern, digital printing process which is usually faster and cheaper than litho printing for small print quantities (but not for large print runs). There are various types including Xerox and Indigo variants. Unlike with litho printing, digital printing does not require printing plates to be made up before the job can commence.
  • Dot gain: a usually unintended but sometimes unavoidable enlargement of the tiny printed dots which make up halftone tints and images.
  • Dot gain compensation: the process of altering tints and halftone dot values so as to mitigate got gain (usually worst in the mid tones).
  • DPI: an abbreviation for Dots Per Inch, a term describing the resolution or screen ruling of an image (halftone) or graphic.
  • DPS: an abbreviation of Double Page Spread (two facing pages of a publication).
  • Duotone: an image (usually photographic) which combines two coloured inks. Sepia-toned and blue-toned photographs are good examples.
  • Duplex: printing both sides of a sheet of paper at the same time.

E

  • Embedding: the process, when preparing digital artwork files, of incorporating any graphics and fonts into the single artwork document/file — rather than linking to multiple separate files. Embedding is preferred by printers as it is more reliable as artwork.
  • Embossing: a raised impression of a graphic, design or lettering made when a letterpress style die is pressed from the back of the sheet under pressure.
  • EPS file: a type of digital artwork file. EPS stands for Encapsulated Postscript and is the industry standard for vector graphics, although is usually embedded within a PDF artwork file (see below).

F

  • Finishing: is where printed jobs undergo their final stages i.e. are converted from flat untrimmed sheets to the final product. Finishing includes any hole drilling or punching, creasing and folding, gluing, trimming, collating and any hand assembly.
  • Flush cover: a book, brochure or other publication whose covers are cut to exactly the same size as the internal pages (so they all line up exactly).
  • Flyer: a simple piece of literature e.g. leaflet, which is produced for promotional purposes in a reasonably inexpensive way.
  • Foil stamping or blocking (a.k.a. hot foil): a method of printing metallic foils e.g. gold or silver foil, although many other foil types are possible including coloured foil, clear foil and even holographic foil. Traditionally hot foiling required a metal die to be used however in recent years modern machines exist which allow hot foiling ‘on the fly’ (The Document Centre have one of these for the foil lettering on hardbound theses).
  • FPO: an abbreviation of ‘For Position Only’ which denotes a graphic or photograph within an artwork or web page which is only temporary.
  • FSC-accredited: applies to a paper or card stock which is usually eco-friendly as accredited by the Forest Stewardship Council.

G

  • Graduation or graduated screen: an area of a graphic, tint or photo where one tone merges seemingly continuously into another tone, without any visible tonal steps.
  • Grain: paper has a ‘grain direction’ (referring to the lay of the fibres making up the paper). Folding across the grain makes for a very sharp, stiff folding. Folding ‘with’ (in the same direction as) the grain makes for a softer fold.
  • Greeking: (used in design visuals or layout applications) uses ‘fake’ text to show the position and perhaps style of real text which will usually replace the greeked text at a later stage. Greeking can be in the form of dummy text such as ‘Lorem Ipsum’ (Latin) text, or perhaps even grey lines.
  • gsm: abbreviation of Grams per Square Meter, being an indication of the weight of paper or card.
  • Guillotine: a machine used to trim or cut paper or card.
  • Gutter: the unprinted space or page margin which sits towards the inner, bound edge of book or publication pages.

H

  • Halftone: photographs or other ‘continuous tone’ images are converted to a series of tiny dots. The size and spacing of the tiny dots results in different tones being replicated to the onlooker. The resulting image is called a halftone and can be lithographically, digitally or inkjet printed without a true photographic process being necessary.

I

  • IBC: abbreviation of Inside Back Cover.
  • IFC: abbreviation of Inside Front Cover.
  • InDesign: a popular design and page layout application made by Adobe.
  • Ivory board: a bright white board (thin card) mostly used for printed business cards.

J

  • Jacket (a.k.a. Dust Cover): the outer protective cover often found on hardbound books, usually made of paper.
  • Justified text: a block of text formatted in such a way that it has both left- and right-aligned vertical edges.

K

  • K is the ‘blacK’ ink colour in 4 colour ‘process printing’. K is used instead of B so as to avoid any confusion with blue (one of the other 4 process colours is cyan, which is a sky blue).
  • Kerning: the spacing between individual letters or ‘characters’. Sometimes automatic kerning needs manual adjustment, for example so that unsightly gaps are closed up.
  • Knockout: where one printed element does not ‘overprint’ another. In contrast a red letter completely overlapping (overprinting) a blue background would otherwise form a purple result. To stop this happening the red letter ‘knocks out’ the blue background, so remains red.

L

  • Laid: a type of uncoated paper which has fine parallel lines of texture on it, usually used for stationery.
  • Laminated: in printing paper and board can be coated with a fine layer of plastic, so it becomes both protected from water etc. and finished in either high gloss or a soft, matt surface. In recent times a silk lamination has also been developed but is less common.
  • Landscape: a paper or image format where the width is larger in size than the height.
  • Letter: (a.k.a. American Quarto): the paper size 215.9mm x 279.4mm
  • Leading (or Linefeed) is the vertical distance between lines of text and is usually measured in points although alternatively might be expressed as a percentage of the text size. On websites it may also be measured in pixels.
  • Letterpress: a comparatively traditional printing process which uses raised metal surfaces to print the ink (often resulting in a slightly indented relief).
  • Line artwork or Line copy: artwork which has no tints and tones. So it’s either 100% black or completely white. The printed result will obviously be incredibly contrasty too. Line artwork is therefore suitable, for example, where you simply have black and white text and lettering on a white background.
  • Litho or Lithographic Printing: the standard/traditional printing method for brochures, leaflets, stationery, etc. This printing process gives the optimum result. Compare to ‘Digital Printing’ (see D section).

M

  • ‘M’ or ‘Magenta’: The rich pink ‘process colour’ used by printers in 4 colour ‘process’ printing (it is the ‘M’ in ‘CMYK’).
  • Make-readies: the printed sheets which are output and scrutinised while the printer settings are still being fine-tuned.
  • Matchprint: a very accurate type of printer’s proof.
  • Moiré: a regular pattern (akin to tartan) formed either when screen angles are incorrect for one or more of the colours being printed, or when an already ‘screened’ photograph or graphic as been ‘re-screened’. Commonly referred to as a ‘screen clash’.

O

  • OBC (or just BC): abbreviation for Outside Back Cover.
  • OFC (or just FC): abbreviation for Outside Front Cover.
  • On-demand printing (or Print On Demand): As the name suggests, this is where printing is produced only when required, rather than printing huge quantities which then need to be stored. Usually only cost-effective when digital presses are used.
  • Orphan: in typography this is where a single line of text appears at the top of bottom of a page, rather than being with the rest of its continuing paragraph. It is considered by many to be poor practice
  • Outlining text: the process where fonts are converted to vectors during preparation of artwork files. Outlining text is a way of minimising any font issues when the file is sent for repro/output.
  • Overprint: This is the opposite of knocking out and refers to the technique where one printed element completely overlaps (and ‘overprints’) another. For example black text on a coloured background is often overprinted because a) it will become a denser black and b) registration would be more tricky if it knocked out the underlying colour. Care must be taken, however, otherwise unexpected colour changes can take place.

P

  • Pantone: The Pantone Matching System is an industry-standard specification for colours. Each colour has a reference code, name or number so that colours remain accurate and as expected, no matter where they are printed.
  • PDF: PDF stands for Portable Document Format and is the industry standard file type for digital artwork (although other formats like EPS, Adobe Illustrator, Adobe InDesign and Quark Express files are also widely used).
  • Perfect binding (a.k.a. adhesive or glue binding): is where the publication pages are held together with a flexible glue applied to the spine (most widely used for paperbacks).
  • Plate (or printing plate): is the flat, usually metal, sheet which, by its nature and make-up, carries the printer’s ink so that it is directly or indirectly deposited accurately on the paper.
  • PMS: an abbreviation of Pantone Matching System (see above).
  • Portrait: a paper or image format where the height is greater than the width.
  • PostScript: the industry-standard coding language for the graphics and printing industries, as embedded in page make-up programmes like Adobe InDesign and Quark Express.
  • PPI: Pixels Per Inch (similar to dots per inch).
  • Process colours: these are the 4 standard printing inks used in full colour printing (litho and most digital). They are Cyan (C), Magenta (M), Yellow (Y) and Black (K). Together they can be used to approximate full colour e.g. photographs and multi-coloured graphics etc.
  • Proof: a single printed sheet produced so as to check the final printing looks as expected.

Q

  • Quark Express (commonly referred to as Quark): a popular, professional page design and layout programme.

R

  • Ream: a term for 500 sheets of paper.
  • Recto (a.k.a. obverse): the odd-numbered page in a book or publication which appears on the right-hand side.
  • Registration marks: are small printers’ marks added to the artwork and printing, outside the document area, which allow the printer to register the various printing inks. They are subsequently trimmed off when the document is guillotined down to its final size.
  • Registration: the process of aligning the various printed colours closely so that the finished result is sharp and colours are in close register.
  • Res: abbreviation of Resolution (see immediately below).
  • Resolution: defines the density of information held within a digital graphics file. Measured usually in dots per inch (DPI) or pixels per inch (PPI).
  • Retouching: the process of enhancing photographs or correcting imperfections in them.
  • RGB: the Red, Green and Blue light used on PC and other screens. You do NOT want any of your artwork or graphics to be in RGB mode otherwise it is unlikely to print as you expect. Convert usually to CMYK mode (see above).

S

  • Saddle-stitching: essentially stapling along the spine (of printed brochures, for example).
  • Set-off spray (a.k.a. anti-offset spray): a dry application sometimes sprayed onto the surface of printed documents during printing so as to reduce or eliminate the chance of ink passing from the face of one printed document to the underside of the next. Used especially when large areas of dense or dark colours are being printed.
  • Score: a linear crease made on paper to aid folding.
  • Screen frequency (a.k.a. screen ruling): in halftones and tints the screen frequency measures or specifies the density or spacing of the tiny regular dots which make up the image.
  • Set-off: a defect caused when ink from the one face of a printed sheet transfers to the other face of the next sheet.
  • Set-off spray (a.k.a. anti-offset spray): a dry application sprayed onto the surface of printed documents so as to reduce or eliminate the chance of ink passing from the face of one printed document to the underside of the next. Used especially when large areas of dense or dark colours are being printed.
  • Show-through: this refers to the printed image on one side of a sheet showing through to the other side. It is usually prevalent in very thin paper, and/or paper which is not very opaque.
  • Spot colours: specially mixed inks which result in a very accurately specified colour, usually to ‘Pantone’ specification. These are used where usual ‘Process Colours’ are not accurate enough to achieve the desired colour, or to save money when a litho job requires only one or two inks (instead of the 4 process colours).
  • Spot varnish: the application of varnish to only parts of a printed job, for example only photographs.
  • ‘SRA’ paper sizes (like SRA3, SRA2 etc): these are oversize ‘A size’ paper sheets used by commercial printers. They are oversize to allow additional bleed, registration and trim marks to be printed outside the document area prior to it being cut down into the final ‘A’ size. ‘RA’ sizes are similar. See http://www.papersizes.org/ra-sra-untrimmed.htm
  • Stock: a common printers’ term for unprinted paper, board or card.
  • Super A3 (or ‘A3+‘) is a paper size of 329mm x 483mm. Known as B+ in the U.S.

T

  • Tints: these are shades of a solid colour made possible through the use of tiny, regularly spaced dots. They are usually specified as percentages e.g. a 10% tint is very pale whereas a 90% tint is an almost solid colour.
  • Thermography: a type of printing which results in the printed ink being raised.
  • Trapping: this is a prepress process where adjoining colours are deliberately made to very slightly overlap so as to minimise the chance of misregistration on the final printed piece.
  • Trim marks: are marks added to the artwork and printing which tell the printer where he will need to trim. They usually appear a few millimetres outside the edges of the final document and are trimmed off when the document is guillotined.
  • Typo: an abbreviation for typographical error.

U

  • Uncoated stock: paper which doesn’t have any coating i.e. no clay compound (compare to Art paper above). Ink printed on uncoated paper tends to absorb into the fibres of the paper itself, resulting in the printed colours appearing flatter, less saturated on a matt finish.
  • UV Varnish: a high gloss varnish applied to a printed job. It is similar in appearance to gloss lamination but can be applied as a ‘spot’ varnish i.e. unlike lamination it does not need to cover the entire side of the sheet.

V

  • Variable data: changing data which can, for example, be used during on-demand digital printing so as to personalise each different print to a particular recipient.
  • Vector graphics: graphics which is mathematically constructed rather than consisting of pixels. Vector graphics can be scaled to any size without loss of quality or sharpness.
  • Verso or reverse: the left-hand page of a book or publication, usually numbered with an even page number.
  • Vignette: the smooth, gradual change of a colour’s tone e.g. from dark to light (or even to invisible).

W

  • Widow: the last word of a paragraph which appears on a line all on its own. Considered poor typographical practice.
  • Wove paper: a smooth uncoated paper without much texture.
  • WYSIWYG: abbreviation for What You See Is What You Get (applicable, for example, to page make-up programmes on computer screens).

X

  • X-height: the part of lower case lettering equal to the height of the lower case x.

Y

  • Y or ‘Process Yellow’: is the Yellow ink in the four ‘process colours’. It is the ‘Y’ in ‘CMYK’.

We hope you find this list of printing terms useful; we may indeed add to it in the future. Of course it goes without saying that we’d be delighted to offer our printing services to you. We offer full colour litho printingdigital printing for shorter print runs and large format printing for things like display work etc. Of course we also do bespoke bookbinding, document binding, book restoration and repair as well as thesis binding for university students. We are based near London Bridge on Southwark Bridge Road, London SE1. Call us on 0207 928 9738 or contact us here if you would like any information or indeed a quotation, without obligation.