Page 32 - Adobe InDesign 2021
P. 32

Change Color Values
         Although there are several default color choices built into the Swatches panel of every
         InDesign file, you are not limited to these few options. You can define virtually any
         color based on specific values of component colors.
             When you are building a page to be printed, you should use CMYK colors.
         The CMYK color model, also called process color, uses subtractive color theory
         to reproduce the range of printable colors by overlapping semitransparent layers of
         cyan, magenta, yellow, and black inks in varying percentages from 0–100.
             In process-color printing, these four colors of ink are imaged (or separated) onto
         individual printing plates. Each color separation is printed with a separate unit of a
         printing press. When printed on top of each other in varying percentages, the
         semitransparent inks produce the CMYK gamut, or the range of possible colors.
         Special (spot) colors can also be included in a job by using specifically formulated
         inks as additional color separations.





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             Using theoretically pure pigments, a mixture of equal parts of cyan, magenta,
         and yellow should produce black. Real pigments,
         however, are not pure; the actual result of mixing
         these three colors usually appears as a muddy
         brown. In the image to the right, the left block is
         printed with 100% black ink. The right block is a
         combination of 100% cyan, 100% magenta, and
         100% yellow inks.
             The fourth color, black (K), is added to the three subtractive primaries to extend
         the range of printable colors and to allow much purer blacks to be printed than is
         possible with only the three primaries. Black is abbreviated as “K” because it is the
         “key” color to which others are aligned on the printing press. Using K for black also
         avoids confusion with blue in the RGB color model, which is used for jobs that will
         be distributed digitally (websites, some PDF files, etc.).
           1.  With gcm-letterhead.indd open, use the Selection tool to make sure the
              shape at the bottom of the page is selected.
               Every shape you create in an InDesign document has a bounding box, which is a
               non-printing rectangle marking the outer dimensions of the shape. (Even a circle
               has a square bounding box, marking the largest height and width of the object.)
               The bounding box has eight handles, which you can drag to change the size of the
               rectangle. If you can see an object’s bounding box handles, that object is selected.


           2.  Click the button at the right end of the Control panel to open the panel
              Options menu.





       42  Project 1: Letterhead Design
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