useful information

Glossary - J

Jacket

The cover in which a hardback book is sold.

Java script

An active script that is incorporated with the HTML of a web site. It controls such functions as rollovers.

Jaw folder

Mechanism on a web press that folds paper into signatures.

JDF

JDF stands for Job Definition Format and is an industry standard designed to simplify information exchange between different applications and systems in and around the graphic arts industry. JDF builds on and extends beyond pre-existing partial solutions, such as CIP3's Print Production Format (PPF) and Adobe Systems' Portable Job Ticket Format (PJTF). It enables the integration of commercial and planning applications into the technical workflow. JDF is a comprehensive XML-based file format and proposed industry standard for end-to-end job ticket specifications combined with a message description standard and message interchange protocol ensuring maximum possible portability between different platforms and ready interaction with Internet-based systems.

JMF

JMF is part of the JDF specification. JMF allows a controller to communicate to a JDF MIS or workflow system information, such as events (start, stop, error), status (available, offline, stalled, etc.), results (count, waste, etc.), and other details, such as who is the current operator.

Jog

To shake a stack of papers, either on a machine or by hand, so that the edges line up. Printers jog the paper to get rid of any dust or particles, and to ensure proper feeding into the press.

Jogging

Vibrating paper stock in order to bring the edges into line prior to trimming. A jogger may be attached to a printing press binder or be a separate unit.

JPEG

Acronym for the Joint Photographic Experts Group. C-Cube Microsystems designed it. It is a lossy form of compression, meaning that it looses information in the compression. It works by averaging areas of adjacent pixels. Ideal for Web use as it handles continuous tone and subtle shifts in colour and tone sensitive subject matter well and produces very small files. Never use on images bound for print, artifacting and pixelisation invariably occur.

Justification

The horizontal positioning of text relevant to the margins. Text can be Left Justified, Centre Justified, Right Justified, or Fully Justified. Centre and Full Justification are the most frequently used in the awards industry.

Justify

The alignment of text along a margin or both margins. This is achieved by adjusting the spacing between the words and characters as necessary so that each line of text finishes at the same point.