About spot and process colors, About spot colors – Adobe Illustrator CS3 User Manual

Page 103

ILLUSTRATOR CS3

User Guide

The range of color encompassed by a color space is called a gamut. The different devices (computer monitor, scanner,
desktop printer, printing press, digital camera) throughout your workflow operate within different color spaces and
each with different gamuts. Some colors within the gamut of your computer monitor are not within the gamut of
your inkjet printer, and vice versa. When a color cannot be produced on a device, it’s considered to be outside the
color space of that particular device. In other words, the color is out of gamut.

“Why colors sometimes don’t match” on page 128

About spot and process colors

You can designate colors as either spot or process color types, which correspond to the two main ink types used in
commercial printing. In the Swatches panel, you can identify the color type of a color using icons that appear next
to the name of the color.

When applying color to paths and frames, keep in mind the final medium in which the artwork will be published,
so that you apply color using the most appropriate color mode.

If your color workflow involves transferring documents among devices, you may want to use a color-management
system (CMS) to help maintain and regulate colors throughout the process.

About spot colors

A spot color is a special premixed ink that is used instead of, or in addition to, CMYK process inks, and that requires
its own printing plate on a printing press. Use spot color when few colors are specified and color accuracy is critical.
Spot color inks can accurately reproduce colors that are outside the gamut of process colors. However, the exact
appearance of the printed spot color is determined by the combination of the ink as mixed by the commercial printer
and the paper it’s printed on, not by color values you specify or by color management. When you specify spot color
values, you’re describing the simulated appearance of the color for your monitor and composite printer only (subject
to the gamut limitations of those devices).

Keep the following guidelines in mind when specifying a spot color:

•

For best results in printed documents, specify a spot color from a color-matching system supported by your
commercial printer. Several color-matching system libraries are included with the software.

•

Minimize the number of spot colors you use. Each spot color you create will generate an additional spot color
printing plate for a printing press, increasing your printing costs. If you think you might require more than four
colors, consider printing your document using process colors.

•

If an object contains spot colors and overlaps another object containing transparency, undesirable results may
occur when exporting to EPS format, when converting spot colors to process colors using the Print dialog box,
or when creating color separations in an application other than Illustrator or InDesign. For best results, use the
Flattener Preview or the Separations Preview to soft proof the effects of flattening transparency before printing.
In addition, you can convert the spot colors to process colors by using the Ink Manager in InDesign before printing
or exporting.

•

You can use a spot color printing plate to apply a varnish over areas of a process color job. In this case, your print
job would use a total of five inks—four process inks and one spot varnish.