Two recently released guides take a closer look at color-characterization data and color measurement
The American National Standards Institute's (ANSI) Committee for Graphic Arts Technologies Standards (CGATS) took a closer look at color-characterization data and color measurement in two recently released guides. The documents deal with setting up press runs for generating color-characterization data and methods for measuring output for valid color data. CGATS Subcommittee 4, which oversees process control, developed the organization's Recommended Industry Practice: Color characterization data set development--Press run guidelines. The recommendation addresses planning, preparation, printing, and post-printing processes that relate to "data that defines the relationship between the CMYK values used to prepare the printing form and the colorimetric output produced by the printing process." In the guidelines, CGATS discusses maintaining documentation, selecting tolerances, and identifying equipment, inks, and substrates, as well as developing a sampling plan and designing a test form. "By ensuring that input variables--i.e., raw materials and process parameters--conform to specified norms, consistent output color is maintained," the document says. The Recommended Industry Practice is available for download at no cost from www.npes.org/standards/workroom.html and includes a sample form that printers can modify to accommodate a specific output method. To help printers further ensure consistent color output, CGATS has revised its 1993 standard, CGATS.5, Graphic Technology--Spectral measurement and colorimetric computation for graphic arts images. The standard specifies a method for measuring images in a way that produces comparable and consistently valid data. The standard applies to material preparation for high-volume output and short-run jobs produced with photographic, inkjet, thermal-transfer, toner, and other printing technologies. CGATS expanded the standard's content regarding sample backing material to include white and self-backing products for use in specific situations. The document offers guidelines on choosing backings and determining substrate opacity, and it specifies requirements for data reporting. CGATS also added an annex on instrument calibration. This standard is available for purchase through NPES, the association for Suppliers of Printing, Publishing, and Converting Technologies. For more information, contact the NPES Publication Department, 703-264-7200, or download an order form on the Web: www. npes.org/standards/orderform.html.
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