Achieving Reliable Print Output from Adobe ... - Adobe Partners

Choosing the proper resolution settings
You should set the resolutions to accommodate target output conditions before flattening. You
can set the resolutions the Flattener uses to match your target output conditions for the following
file types that contain live transparency:
• Native Illustrator 10 and CS (.AI)
• PDF 1.4 or 1.5 files directly created from Illustrator 9, 10, or CS; InDesign 2, or CS; and
Acrobat 5 or 6 Professional. Note that any PDF file created with Acrobat Distiller software
will not contain live transparency because Distiller processes PostScript to create a PDF and
PostScript cannot contain live transparency.
• EPS from Illustrator 9, 10, and CS (the file must have been saved with the Preserve Illustrator
Editing Capabilities option chosen, and it must be opened in Illustrator).
• PDF 1.3 from Illustrator 9, 10, and CS (the file must have been saved with the Preserve
Illustrator Editing Capabilities option chosen, and it must be opened in Illustrator).
Basic guidelines for setting Flattener resolutions
Although your workflow requirements may vary, the following general guidelines will help you
choose the proper resolution settings for your files:
The Line Art and Text Resolution should be based on the resolution of your output device. To
achieve the highest quality output, you should set the Line Art and Text Resolution to be equal to
the resolution of the output device. In many cases you can reduce the size of the output file and
flattening time—without a significant reduction in quality—by setting this resolution to exactly
one-half of the resolution of the output device. InDesign CS, for example, uses a value of 1200
dpi for its built-in high resolution flattener preset. This resolution is appropriate for use with an
output device that has a resolution of 2400 dpi. The Flattener also uses this value as the upper
limit for rasterizing atomic regions in all transparency-savvy applications.
Creating a customized high-resolution flattener
preset
You may wish to make your own variation of the
high-resolution Flattener preset. For example, if your
device has an output resolution of 2540 ppi, you
might create a preset with a Line Art and Text resolution
of 1270 or 2540 ppi.
The Gradient and Mesh Resolution should match what is commonly used for drop shadows
created in Photoshop (for example, 150 ppi). InDesign CS uses this value when it flattens drop
shadows and feather effects applied to page objects. The Flattener also uses this value as the lower
limit for rasterizing atomic regions in all transparency-savvy applications.
Note that this is the same value that applications already use for rasterizing meshes and gradients
when printing documents to RIPs that don’t support the PostScript 3 smooth shading feature.
The Document Raster Effects Resolution (Illustrator only) should match what is commonly
used for drop shadows created in Photoshop (for example, 150 ppi). This value applies to all raster
effects used in Illustrator, including live raster effects and resolution-dependent filters, such
as Gaussian Blur.
Rasterization and resolution settings
Previous pages of this guide discuss flattening and rasterization in broad terms. The following
section discusses rasterization in greater detail.
The following is a list of situations in which the Flattener may rasterize vector elements:
Flattening atomic regions Flattening divides the transparency of a document into a collection of
discrete areas called atomic regions. If an atomic region contains an image or multiple transparent
gradient or mesh objects, the region is rasterized. The Flattener applies the Gradient and
Mesh Resolution to this region unless it contains one or more images, in which case it applies the
maximum of their resolutions, up to the current Line Art and Text Resolution. The Flattener also
clips the resulting raster with the affected region’s outline, thus preserving its shape in a resolution-independent
form.
Flattening complexity regions A complexity region is an area that isn’t retained in vector form
except at the highest-fidelity Raster/Vector Balance setting. Complexity regions are typically
made up of a large number of objects that interact with transparency. Flattening a complexity
region involves rasterizing all vector objects, images, and text inside it at the Line Art and Text
Resolution. For this reason, make sure to set the Line Art and Text Resolution to a value that
closely matches the characteristics of the chosen output device.
Achieving reliable print output from Adobe
applications when using transparency
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