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                                                     969
            SECTION 10.10                                                          Prepress Support



KEY               TYPE              VALUE

Colorants         dictionary        (Optional; PDF 1.4) A dictionary identifying the individual colorants
                                    associated with a printer’s mark, such as a color bar. For each entry in this
                                    dictionary, the key is a colorant name and the value is an array defining a
                                    Separation color space for that colorant (see “Separation Color Spaces” on
                                    page 264). The key must match the colorant name given in that color space.


10.10.3 Separation Dictionaries

            In high-end printing workflows, pages are ultimately produced as sets of separa-
            tions, one per colorant (see “Separation Color Spaces” on page 264). Ordinarily,
            each page in a PDF file is treated as a composite page that paints graphics objects
            using all the process colorants and perhaps some spot colorants as well. In other
            words, all separations for a page are generated from a single PDF description of
            that page.

            In some workflows, however, pages are preseparated before generating the PDF
            file. In a preseparated PDF file, the separations for a page are described as sepa-
            rate page objects, each painting only a single colorant (usually specified in the
            DeviceGray color space). When this is done, additional information is needed to
            identify the actual colorant associated with each separation and to group together
            the page objects representing all the separations for a given page. This informa-
            tion is contained in a separation dictionary (PDF 1.3) in the SeparationInfo entry
            of each page object (see “Page Objects” on page 144). Table 10.50 shows the con-
            tents of this type of dictionary.

                               TABLE 10.50 Entries in a separation dictionary
KEY                TYPE        VALUE

Pages              array       (Required) An array of indirect references to page objects representing separa-
                               tions of the same document page. One of the page objects in the array must be
                               the one with which this separation dictionary is associated, and all of them must
                               have separation dictionaries (SeparationInfo entries) containing Pages arrays
                               identical to this one.

DeviceColorant     name or     (Required) The name of the device colorant to be used in rendering this separa-
                   string      tion, such as Cyan or PANTONE 35 CV.

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