PDFlib 8 Windows COM/.NET Tutorial

Cookbook A full code sample can be found in the Cookbook topic color/color_gradient.
3.5.2 Pantone, HKS, and custom Spot Colors
PDFlib supports spot colors (technically known as Separation color space in PDF, although
the term separation is generally used with process colors, too) which can be
used to print custom colors outside the range of colors mixed from process colors. Spot
colors are specified by name, and in PDF are always accompanied by an alternate color
which closely, but not exactly, resembles the spot color. Acrobat will use the alternate
color for screen display and printing to devices which do not support spot colors (such
as office printers). On the printing press the requested spot color will be applied in addition
to any process colors which may be used in the document. This requires the PDF
files to be post-processed by a process called color separation.
PDFlib supports various built-in spot color libraries as well as custom (user-defined)
spot colors. When a spot color name is requested with makespotcolor( ) PDFlib will first
check whether the requested spot color can be found in one of its built-in libraries. If so,
PDFlib will use built-in values for the alternate color. Otherwise the spot color is assumed
to be a user-defined color, and the client must supply appropriate alternate color
values (via the current color). Spot colors can be tinted, i.e., they can be used with a
percentage between 0 and 1.
By default, built-in spot colors can not be redefined with custom alternate values.
However, this behavior can be changed with the spotcolorlookup parameter. This can be
useful to achieve compatibility with older applications which may use different color
definitions, and for workflows which cannot deal with PDFlib’s Lab alternate values for
PANTONE colors.
PDFlib will automatically generate suitable alternate colors for built-in spot colors
when a PDF/X or PDF/A conformance level has been selected (see Section 10.3, »PDF/X
for Print Production«, page 253). For custom spot colors it is the user’s responsibility to
provide alternate colors which are compatible with the selected PDF/X or PDF/A conformance
level.
Note Built-in spot color data and the corresponding trademarks have been licensed by PDFlib GmbH
from the respective trademark owners for use in PDFlib software.
Cookbook A full code sample can be found in the Cookbook topic color/spot_color.
PANTONE® colors. PANTONE colors are well-known and
widely used on a world-wide basis. PDFlib fully supports the
Pantone Matching System® (totalling ca. 26 000 swatches),
plus the Pantone® Goe System which was introduced in
2008 with 2058 additional colors in coated/uncoated variants.
All color swatch names from the digital color libraries
listed in Table 3.4 can be used. Commercial PDFlib customers
can request a text file with the full list of PANTONE spot color
names from our support.
Spot color names are case-sensitive; use uppercase as shown in the examples. Old
color name prefixes CV, CVV, CVU, CVC, and CVP will also be accepted, and changed to
the corresponding new color names unless the preserveoldpantonenames parameter is
true. The PANTONE prefix must always be provided in the swatch name as shown in the
3.5 Working with Color 81