Adobe 65023809 - Creative Suite 4 Master Collection Printing Manual page 83

Spot-color 3D Objects
When performing 3D operations on a spot-color object, display the additional options in the 3D dialog box for
more controls . To avoid converting spot-color content to CMYK, check the Preserve Spot Colors option . At first,
the object will appear as black only; for correct display, activate Overprint Preview (View > Overprint Preview) .
To maintain spot-color content in 3D objects, Illustrator uses overprint. Essentially, the object is
replicated by two separate objects—a solid object filled with the spot color, plus a grayscale (black
only) object carrying the shading and set to overprint. This arrangement will initially appear to
be black only, until you turn on Overprint Preview (View > Overprint Preview). Since overprint
must be processed for the object to print correctly in the spot color and black, the RIP must allow
PostScript overprint to be active.
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Retaining Spot Color
For output, Illustrator renders a spot-color 3D object as two elements—a group of black-only objects, set to
overprint, and a solid object filled with the spot color . You must turn on Overprint Preview to view this effect
correctly, and the output device must honor the overprint instruction to image the objects correctly .
We have used an extruded object as the example, but the same rules apply to rotated and
revolved 3D objects.
Expanding 3D objects
A live 3D object in Illustrator is a simple cross section under the hood. While this allows you
to edit the basic cross section shape (and thus the shape of the 3D object), you cannot select
individual, shaded areas for editing, because they are not literal, individually editable vectors. To
convert the live effects to editable vectors, expand the object (Object > Expand Appearance). The
result can be a collection of very complex objects, but you gain some editability for individual
components, and often a reduction in file size. If you must expand a 3D object, it is recom-
mended that you work on a copy of the file, and keep an unedited original as insurance.
Adobe Creative Suite 4 Printing Guide 81