Standards 101

Blind exchange: An exchange of printing information (digital data files) in which the sender and receiver do not require advance communication to properly process the information and produce the expected results. 

CGATS: (Committee for Graphic Arts Technologies Standards): The standards committee responsible for graphic technology standards within the USA. NPES The Association for Suppliers of Printing, Publishing and Converting Technologies serves as the secretariat of this committee. 

CMYK: The printing industry generally uses Cyan, Magenta, Yellow, and Black ink in combination to create the visual impression of full colour images.

Colour managed workflow: A method of exchanging image information where input and/or output device data spaces are related to a colorimetrically defined reference space through transforms carried in "profiles" (see ICC).

DDAP (Digital Distribution of Advertizing for Publications): An international industry group formed to support and publicize the use of accredited standards for the distri - bution of advertising in the ublication segment of the printing and publishing industry.

FAQ (Frequently Asked Questions): Listings of frequently asked questions and their answers often found on Web sites.

ICC (International Colour Consortium): An industry group developing an architecture and data formats to enable open exchange of colour information.

ICC Device Profile: The collection of transforms necessary to relate device colour data of input, display and output devices to the colorimetrically defined profile connection space.

Object data: Imaging data that is created by a series of vector line segments and/or fill commands to create graphical elements, text, etc.

OPI (Open Prepress Interface Specification): A method by which the creator of a document will use a low resolution image as a place holder which will later be replaced by a image with sufficient resolution for quality printing. Image files with sufficient resolution for printing generally are generally about 60 kilobytes per square centimetre.

PDF (Portable Document Format): A format developed by Adobe Systems Incorporated that builds on the PostScript page description language and layers a document structure and interactive navigation features on its underlying imaging model.

PDF/X: A family of graphic technology standards that standardize the used of the Adobe PDF for eXchange of print-ready material.

PDF/X-1 (ISO 15930-1): Complete exchange of CMYK data.

PDF/X-2 (ISO 15930-2): Exchange of CMYK and/or colour managed data where some of the data required for final output (e.g. fonts, high resolution picture data, etc.) is uniquely identifed but exchanged separately from the main body of the data exchange.

PDF/X-3 (ISO 15930-1): Complete exchange of CMYK and/or colour managed data.

Raster data: Imaging data that is organized into sequential lies of information that are displayed one following the other as in a television display.

RGB: Red, green and blue are the colours obtained from an image scanner and/or used to drive a computer monitor. They are also the colours used in many computer imaging and drawing packages.

TIFF and TIFF/IT: A file format that uses "tags" to carry information about the data content and structure of the file.

Transforms: See ICC Device Profile.

Further information: There are a number of useful Web sites available that provide additional information about PDF/X and related issues. ISO/TC 130/WG 2 and CGATS information can be found at www.npes.org/standards/workroom.html. The Digital Distribution of Advertising for Publications (DDAP) Association site, www.ddap.org, is also a good general source for information about TIFF/IT and PDF/X and their use in the United States publication marketplace. An excellent FAQ on PDF/X, by Martin Bailey of Global Graphics, can also be found on the DDAP Web site at ww.ddap.org/resources/pdf_x_faqs.html. (Martin is the chair of both the CGATS and ISO task forces working on PDF/X.)