Overview
ISO 12642-1:2011 - Graphic technology - Input data for characterization of four‑colour process printing - Part 1: Initial data set - defines a standard input data file, a measurement procedure, and an output data format for characterizing any four‑colour (CMYK) half‑tone printing process (including gravure). The part provides digital ink‑value palettes and guidelines to enable unambiguous colour characterization, exchange and reuse of device‑specific print data for color management and process control.
Key topics and technical requirements
- Ink value data sets: Two predefined palettes are specified
- Basic ink value data set (182 colour samples) - the default, compact set for common modelling methods.
- Extended ink value data set (928 colour samples) - larger palette for more comprehensive characterization.
- A user‑defined data set is also permitted when special process needs arise.
- Measurement procedures: Specifies how to obtain colorimetric data (CIE tristimulus values X, Y, Z) for the ink‑value combinations, including requirements for linearization of film/half‑tone values and handling of film generations.
- Data format and exchange: Defines keyword/value file concepts and points to ISO 28178 for the exchange format (XML or ASCII text) used to carry characterization and process‑control data.
- Scope of characterization: Covers all production steps (separations, platemaking, contacting) that affect final print colour; intended to support conversion to device‑independent colour or adaptation to different printing conditions.
- Practical measurement guidance: Includes application notes (Annex A) on palette selection, modelling vs. full‑palette measurement, and considerations for non‑typical inks or non‑half‑tone processes.
- Interoperability: Technical content is aligned with ANSI IT8.7/3‑1993 and references ISO 13655 for spectral measurement and colourimetric computation.
Practical applications and intended users
ISO 12642-1:2011 is used by:
- Prepress and colour management engineers creating or validating CMYK characterization files and ICC profiles.
- Print service providers who need standardized exchange of device‑specific colour data between workflow systems.
- Software vendors implementing colour conversion, proofing, or process‑control modules.
- Laboratories and standards bodies documenting legacy characterization data (this Part 1 is essential for validating earlier datasets).
Typical applications include device characterization, colour proofing, process control, and conversion of CMYK image data to device‑independent colour representations.
Related standards
- ISO 13655 - Spectral measurement and colorimetric computation for graphic arts (normative reference).
- ISO 28178 - Exchange format for colour and process control data using XML or ASCII text (data‑exchange format referenced).
- ISO 12642‑2 - Expanded data set (larger/more recent palette; often preferred for new characterizations).
Keywords: ISO 12642-1:2011, four‑colour process printing, CMYK characterization, ink value data set, colour characterization, CIE tristimulus, ISO 28178, ISO 13655.