User Guide

CHAPTER 5
96
Reproducing Color Accurately
4 Calculate the required adjustment, and type the
values (as percentages) in the Transfer Functions
dialog box.
For example, if you specified a 50% dot, and your
imagesetter prints it at 58%, an 8% dot gain occurs
in the midtones. To compensate for this gain, enter
42% (50% – 8%) in the 50% text box of the
Transfer Functions dialog box. The imagesetter
then prints the 50% dot you want.
When entering transfer function values, keep in
mind the density range of your imagesetter. On a
given imagesetter, a very small highlight dot may
be too small to hold ink. Beyond a certain density
level, the shadow dots may fill as solid black,
removing all detail in shadow areas.
Note: To preserve transfer functions in an exported
EPS file, select Override Printer’s Default Functions
in the Transfer Functions dialog box and then export
the file with Include Transfer Functions selected in
the EPS Format dialog box. (See“Saving files in
Photoshop EPS or DCS format” on page 315.)
To save the current transfer function settings as
the default:
Hold down Alt (Windows) or Option (Mac OS) to
change the Save button to —> Defaults, and click
the button.
To load the default transfer function settings:
Hold down Alt (Windows) or Option (Mac OS) to
change the Load button to <— Defaults, and click
the button.
Setting the characteristics of custom ink
colors
In most cases, the Ink Colors options in the CMYK
Setup dialog box accurately describe various
printing inks. In some situations, however, you
may want to adjust the ink colors further by using
a color proof. For example, you may be using ink
sets not listed for Ink Colors. When you change
these settings, you change the profile of the inks
Photoshop uses during the color separation.
To adjust for custom ink colors:
1 Choose File > Color Settings > CMYK Setup.
2 For Color Model, choose Built-in.
3 For Ink Colors, select Custom.