Printing Jargon: What does it mean?

This is a list of the more common terms.

Artwork

Term to describe the digital representation of the customer’s piece of marketing collateral. This digital representation can be put together in many software packages including Indesign and QuarkXpress.

Biodegradable

A substance that will decompose as the result of action by bacteria and other living organisms.

Bleed

The part of a printed page that extends beyond the trim size or finished size of the printed piece.

Blind emboss

A logo, text or design which has been relief stamped into a sheet of paper, onto which no printing ink has been added.

Case binding

Section sewn books bound with hard board (case) covers.

CMYK

The four colours making up a standard set of inks used on a modern lithographic press: Cyan (blue), Magenta (red), Yellow (yellow) and Key (black).

Coating

In-line water based surface coating that protects the ink from rubbing and enables quick handling. It is thicker and gives a superior feel to varnish

Creep

When you fold a single piece of paper a number of times two things happen. Firstly the folded item gets thicker and secondly the middle pages start to extend beyond the outside pages. This extension is important because without adjustment, the trimmed final book will have common elements on the middle pages (for example page numbers) appearing closer to the fore edge than on the outside pages.

Cross over

Type or image that continues from the left hand page of a book or magazine across the spine to the right hand page.

Deboss

As emboss but recessed into the substrate.

Die cut

A process to cut, score or perforate a flat printed sheet.

Dot Gain

Each dot on the plate carries ink which is transferred onto the paper using offset. As the ink coats the paper it tends to spread. The percentage that the printed dot is larger than the dot on the plate is called dot gain.

DPI

Stands for dots per inch, usually in the context of halftones or process printing, which refers to the frequency of dots appearing on the plate. The greater the DPI the finer the print.

Drawdown

Test of ink colour before going to press. Solid stripes on the correct substrate to show what the ink colour will look like.

Dust jacket

A loose cover to protect the boards on a case bound book.

Emboss

A design stamped with or without ink or foil onto a substrate giving a raised surface.

Endpapers

Printed or plain sheets of paper that attach the inside pages of a book to its cover.

Flush cover

Book or booklet having the cover trimmed to the same size as the text.

Foil block

An off line process (ie happens after printing) to attach foil in a predetermined shape to the printed page.

Folio

Page number on each page.

Fore Edge

The outer edge of a bound publication opposite the spine.

FSCĀ®

The Forest Stewardship Council (FSCĀ®) trademark provides International recognition to organisations who support the growth of responsible forest management.

Grain direction

Direction in which the majority of the fibres in a piece of paper or board are aligned.

GSM or g/m2

Both stand for grammes per square metre, g/m2 is the correct definition by paper manufacturers but GSM is used more frequently.

Half perf

A perforation line usually running across the page but not to the full width of the page.

HalfTone

The basis of lithographic printing. Each colour separation is sent through a RIP and converted into different sizes of, but all very small, dots. These dots cannot be detected by the human eye which is fooled into seeing a continuous image on the printed sheet. This array of dots is called a halftone image.

Hickies

Imperfections in printing due to debris in the ink or paper.

Hybrid screen

A screening technology made up of two different screen algorithms. Usually this is a combination of AM (conventional screening) and FM (stochastic screening). The technology seeks to combine the advantages of each and allows print to a higher definition (ie using smaller dots).

Imposition

The process of arranging pages correctly on the flat sheet prior to printing so that when folded the pages appear in the correct order.

ISO 12647

The printing standard determines the colour of the CMYK inks and the dot gain allowed on the printed sheet.

Kiss cut

A light die cut that cuts through the first layer but leaves the base substrate uncut.

Leaf

A sheet of paper containing two pages, one on either side.

Matt & Gloss varnish

A Wood Mitchell specialist coating process providing high levels of contrast between pre-selected areas of matt and gloss on the finished pages. The process is more accurate than spot UV and unlike spot UV can be used for vignettes and soft edges.

Microns

A measurement to indicate the thickness of paper as against grammage which is a measurement for weight only.

Micro perf

A very finely cut perforated edge, designed to simulate the effect of a guillotine cut edge.

Offset

The most commonly used printing method. The image is transferred from plate to blanket to impression cylinder to paper. Thereby the image is being offset.

Perfect binding

The sections of a book are formed into a block and the binding edge is ground off, notched and glued as the cover is drawn on to the block. This glue holds them together without the use of stitches.

Perfecting

Printing both sides of the substrate in the same pass through the printing press.

Plate

One printing plate (normally aluminium but can be plastic) carries the halftone dots for one colour. A printing press capable of printing full colour will usually have at least four printing units with one plate on each unit. The surface of the plate is covered with ink and water on each revolution of the cylinder within the printing unit. The ink only sticks to the image area (ie each dot) and water sticks to the non-image area to allow control over the print.

PUR binding

Similar to perfect binding, it is slightly more expensive but with superior strength.

Ream

250 sheets of paper.

Recycled paper

Paper made all or in part from recycled pulp. The pulp is made from waste paper or board and may or may not be de-inked. The quality of the fibres deteriorates with recycling, so paper cannot be endlessly recycled.

RIP

Raster Image Processor (RIP) converts a digital file into dots that can be imaged onto a plate.

Rollercoat UV varnish

A varnish which is applied all over the printed surface unlike spot uv which is applied to specific areas.

Screen

Screening is the art of being able to use only three solid tint colors and black as a contrasting color to simulate a natural-looking color image. This is achieved by printing dots which are too small for the eye to see in, predominantly, two different patterns. Conventional or AM screening gives an array of dots, which are set out in a regular lattice looking like a 2 dimensional crystal structure, of different size. FM or frequency-modulated screening sets out dots of the same size in a random pattern.

Bizarre optical effects can arise within AM printing from the angle of the lattice (screen angle) of each colour but modern techniques have all but eliminated this issue.

Self cover

A cover made out of the same paper stock as the text pages.

Separations

The digital file which holds the finished artwork is separated using software into the 4 CMYK colours that the press is capable of printing.

Show through

The degree to which printing is visible through paper due to the low opacity of the paper.

Spot colour/Special colour

A printing ink specially mixed to give a specific colour, including metallic or fluorescent inks. Customers may have a corporate colour which must be accurately printed and is not suitable for CMYK separation.

Thread sewn

A more expensive form of binding. The sections of a book block are sewn together prior to being bound to give added strength and improved flexibility.

Tip in

An insert attached to a publication by gluing along the binding edge.

Varnish

An extra ink that is transparent can be used to protect the wet colour inks sitting on the surface of the paper. Coated papers come in three different finishes which absorb the ink to varying degrees. Matt and silk papers do not easily absorb ink and a varnish is applied to protect the still wet ink from rubbing or sticking during later manufacturing processes. Gloss paper absorbs ink more readily and does not tend to need a varnish protection.

Vignette

Fade to white of illustration or colour in which the tones gradually fade away.