A Sizes

A common range of paper sizes.
A0 – 841 x 1189mm
A1 – 594 x 841mm
A2 – 420 x 594mm
A3 – 297 x 420mm
A4 – 210 x 297mm
A5 – 148.5 x 210mm
A6 – 105 x 148.5mm


A computer image file composed of a matrix of dots called pixels. There are many different bitmap file types such as TIFF, JPEG & PNG.


The printed image extends beyond the trim edge of a sheet or page.

C Sizes

Paper sizes used for envelopes, designed to take A size paper.  For example, a C5 envelope fits an A5 document.

Carbonless Paper (NCR – No Carbon Required)

A special type of coated paper used for invoices and receipts that allows writing to be duplicated onto other sheets underneath without the need for carbon to be inserted.


Abbreviation for cyan, magenta, yellow and key (black).  The four basic colour inks (or toners) used in printing to create full colour documents.

Crop marks

Lines printed showing the dimensions of the final printed page.  These marks are used for final trimming.

Digital printing

Professional printing where desktop publishing and other digital sources are printed using large-format and laser or inkjet printers. It is suitable for shorter run jobs.

DL Size

A paper size measuring 99 x 210mm (a third of A4 size).  It is also a size of envelope.


The number of dots per inch in a picture.  The higher the dpi, the more detailed the image.


A fully sealed clear plastic film to both surfaces of a sheet to enhance its durability.

GSM (grams per square metre)

Unit of measurement used to measure paper weight (and so thickness) in printing.  Paper beyond a certain weight (usually over 170gsm) is card or board.


The arrangement of pages on a printed sheet so that when the sheet is printed on both sides, folded and trimmed, the pages will be in the correct order.


ISBN stands for International Standard Book Number and is a unique 13 digit number assigned to a book by the Publisher to facilitate ordering and tracking.

Lithographic printing

Method used in high-volume commercial printing.

Optical Character Recognition (OCR)

The conversion of scanned images of printed or typewritten text into computer readable text.


Portable Document Format – a file format which should display exactly the same on any computer and is often used to send artwork to printers.


The level of detail in an image measured in dpi (Dots per inch).


Abbreviation for red, green, blue.  Colour model used by electronic display devices such as televisions and computer screens.  Red, green and blue light are added together to produce a broad range of colours.