useful information

Glossary - I

Icons

Graphic elements used instead of something else, typically words or commands. Also Graphic representations of links to locations in a Web site. Icons visually reflect the purpose of the link, such as a house to represent the Home page. In computer operating systems they are pictorial images on the screen indicating functions, files, folders or applications software - generally activated by an on-screen pointer controlled by a GUI device (Graphical User Interface) i.e. a mouse or trackball.

ID

Inside diameter.

Idler rolls

Roller mechanisms on converting machines used to support, smooth or direct the web in its course of travel through a machine. Not driven.

Illustrator

An individual who draws or paints images for use in commercial art. Many new tools allow a variety of expressions with traditional media or new computer enhanced illustration techniques.

Imagesetter

A high-resolution device that prints directly to plate ready film. Many image setters output film at 2400 DPI (dots per inch).

Imagesetting

Imagesetting is the new word for phototypesetting. Today's imagesetters do more than just set type: they set images and graphics, as well, through PostScript, the standard for controlling laser printers. Most imagesetters were designed to be used in digital pre-press and are capable of reproducing colour photographs and graphics in great detail. The main advantage of an imagesetter over a laser printer is that they print at between 1200 and 5000 dots per inch (versus 300-600 for laser printers). Imagesetters also output directly to film, which is more stable than paper, and at much larger sizes: some imagesetters can output 20"x24" or larger.

Impact Printing

Any printing systems where a micro processor controlled drives a ribbon into contact with the print surface (dot matrix) or the print surface into contact with the ribbon drum printer).

Imposition

The arrangement of pages on a printed sheet which - when the sheet is finally printed on both sides, folded and trimmed - places the pages in the correct order ensuring the text reads continuously.

Impress

A page description language developed by Imagen and supported by over 60 software products including Crystal, TeX, Superpage and AutoCAD. Almost certainly the first commercially available PDL.

Impression

The image transferred from the printing plate to the substrate or the adjustment required to affect the same.

Impression cylinder

The cylinder of a printing machine which brings the paper into contact with the printing plate or blanket cylinder.

Imprimatur

'Let it be printed' Latin. In early works it was the statement indicating that the publication was authorised by the appropriate authority.

Imprint

Required by law if the book is to be published. Shows printer's name, location and date of publication.

Imprinting

Technique which applies variable copy to blank or pre-printed labels with a secondary device.

Incanabula

Refers to printed material produced before 1500.

Inch

A unit of measurement equal to six (6) picas or seventy two (72) points.

Indentation

Refers to any measure short of the column width.

InDesign

The next-generation desktop publishing program from Adobe. See PageMaker, QuarkXPress.

Index holes

See feed slots.

Index Paper

A stiff, inexpensive paper with a smooth finish. The high bulk but low weight of this paper makes it a popular choice for business reply cards. The basic size of index paper is 25.5"x30.5".

India paper

Thin strong paper used for Bibles and dictionaries.

Infeed nip

A mechanism designed to control the forward travel of the web into the press.

Inferior letters

Those printed below the base line, as in chemical formulae.

Information Architecture

The design of the hierarchy of Web site around information delivery and usability.

Infrared

The band of light wavelengths too long to be seen by the human eye. Represented by waves that are between 750 and 4 million Nanometers.

Ingredients of Paper

All the materials used to make the mat of fibers known as paper. The one essential ingredient is cellulose fiber. The rest of the ingredients enhance the paper adding body, reducing cost, or changing colour.

Ink

Colour, other than the colour of the paper, is produced by ink. Colour printing falls into three broad categories: SPOT colour, using pre-mixed inks - e.g. PANTONE, the advantage is the precise control available as they are specified in swatch books. PROCESS colour work - four-colour process, Cyan, Magenta, Yellow and Black. A combination of Spot and Process. Inks are made up of three basic ingredients: Pigment - the colour: Vehicle - carries the pigment and the Drying Agent. Ink qualities also depend on what process the ink is intended for. Lithographic and letterpress inks are thick bodied, body referring to viscosity, or stiffness. Such inks become more fluid and softer after they warm up. generally the faster the press the greater the viscosity required. Inks also need the quality of Tack, or stickiness. This plays a role in picking (where the particles of the paper surface are pulled off and collect on the plate and/or blanket leaving white dots in printed areas) trapping and sharpness of print. In multi colour printing the tack must vary between inks, with first down having the highest level of stickiness. The stranding caused by two sticky materials is referred to as length - with long inks being used on newsprint. If an ink is too short it will build up on the press. Drying is from a combination of some or all of the following: absorption into the paper, oxidation, evaporation, heat and UV curing. The final appearance of the job depends on correct drying.

Ink Absorption

Capacity to accept or absorb ink.

Ink Holdout

Resistance to the penetration of ink. Coated papers tend to have good ink holdout. The ink pigments sit on the surface of the coating, and are not absorbed into the spaces between the paper fibers. This minimizes dot spread and results in a sharp image.

Uncoated papers tend to absorb ink into the sheet, but printers can compensate for this and still produce a very bright, sharp image on uncoated paper.

Ink Jet

A method of printing using liquid ink projected a drop at a time against a substrate.

Ink jet printer

A printer that sprays ink in a precise pattern on the page to achieve its output.

Inline graphic

A graphic that is locked to text so that it moves as preceding text is edited or deleted. Useful for captions, as they will not become separated from the picture.

In-line press

A press coupled to another operation such as sheeting, die-cutting, creasing, etc. A multi-colour press in which the colour stations are mounted horizontally in a line.

Insert

An instruction to the printer for the inclusion of additional copy.

Insertion point

Blinking vertical line indicating where the next keystroke will add or delete text.

Intaglio

A method of printing in which an image or letter is cut into the surface of wood or metal, creating tiny wells. Printing ink sits in these wells, and the paper is pressed onto the plate and into the wells, picking up the ink.

Interface

The circuit, or physical connection, which controls the flow of data between a computer and its peripherals.

Interlacing

Progressive display of a graphic in increasing detail as it downloads.

Interleaved bar code

A bar code in which characters are paired using bars to represent the first character and spaces to represent the second.

International paper sizes

The International Standards Organisation (ISO) system of paper sizes is based on a series of three sizes A, B and C. Series A is used for general printing and stationery, Series B for posters and Series C for envelopes.

Internegative

Photographic negative from which a print or transparency is made.

Internet

Or the Net, worldwide system of computer networks allowing one computer to get information from another, with permission. Conceived by Advanced Research Projects Agency (ARPA) - a US Government initiative - in 1969. The original aim was to create a network for university departments to communicate research material.

InterpolationThe estimation of a value between two known values and the resulting colour value that is assigned to a pixel. This is what a programme like Photoshop does when an image is enlarged. It makes an educated guess at what the colour should be based on the surrounding pixels.

Intranet

An internal web site for the use of a company, usually password protected. Used to disseminate internal information such as stock levels and availability.

IP

Internet Protocol; implements the network layer (layer 3) of the protocol, which contains a network address and is used to route a message to a different network or sub network. Plus, accepts ‘packets’ from the layer 4 transport protocol (TCP or UDP), adds its own header to it and delivers a ‘datagram’ to the layer 2 data link protocol.

ISBN

International Standard Book Number. A reference number given to every published work. Usually found on the back of the title page.

ISDN

Integrated Services Digital Network: Internet connection at higher speeds than normal phone lines.

ISP

Internet Service Provider - whose function is to host websites for clients, provide email facilities and access to the WWW for people to browse. For hosting purposes the ISP provides specialised, fast computers, and allocates space on a rental basis.

Some ISPs try to be all things to all people, others specialise and only host Web sites, providing such "server side" benefits such as auto responders, CGI scripts and SSL e-commerce security.

Italic

Type with sloping letters.

Ivory board

A smooth high white board used for business cards etc.