Flattening Transparency in Adobe Acrobat Pro
What are transparencies?
Transparency in PDF files refers to objects on a page, such as images
or text, which are transparent or ‘show through’. Transparency is
typically used for shadow effects, to lighten (parts of) images so that
the text on top remains readable, to make objects fade into another
object or to create a tint of a certain color.
The transparent objects that are in a PDF need to go through a process
called “flattening”, this ensures the best results for your ad to print high
quality as expected. This document will give you the “best practice”
steps to successfully flatten your PDF(s) to ensure compatibility with
high quality printing, utilizing Adobe Acrobat Pro versions 9 and
X. The screen shots included are taken in Acrobat Pro running in
MacOSX, but apply to PC versions as well.
Step 1 - Color separations - Acrobat 9 Pro
In Acrobat Pro 9, open the “Output
Preview...” tab by selecting:
Advanced/Print Production/Output Preview...
This will open a popup window that shows
the color separations that are used in the PDF.
This Output Preview window shows that this
PDF contains 4 process color separations and is
ready to flatten the file as listed on Step 2.
If your PDF contains more than 4 separations, they will need
to be converted to 4/c process colors.
If the extra color separations are not converted, the file may
produce undesired results.
See page 5.
* Please note: while showing “All”, any graphics that are
not CMYK will be previewed using the Simulation Profile.
Step 1 - Color separations - Acrobat X Pro
In Acrobat Pro X, open the “Output
Preview...” tab by selecting the Output
Preview tool. If the Output Preview tool is not
available in your toolbar, Control/Click or
Right-Click on the toolbar to select “Quick
Tools...” The Output Preview tool can now be
added to your toolbar.
This will open a popup window that shows
the color separations that are used in the PDF.
This Output Preview window shows that this
PDF contains 4 process color separations and is
ready to flatten the file as listed on Step 2.
If your PDF contains more than 4 separations, they will need
to be converted to 4/c process colors.
If the extra color separations are not converted,
the file may produce undesired results.
See page 5.
* Please note: while showing “All”, any graphics that are
not CMYK will be previewed using the Simulation Profile.
Step 2 - Flattening your PDF - Acrobat 9 Pro
Open the “Flattener Preview” window
in Acrobat by going to Advanced/
Print Production/ Flattener Preview.
2 Transparency Flattening in Acrobat Professional
Step 2 - Flattening your PDF - Acrobat 9 Pro
With the Flattener Preview window open, make sure the following
settings are applied:
Highlight Transparent Objects
This will highlight any element that has
transparency applied to it. If the entire page is
affected, it will all be highlighted in red.
Preset:
Set this to [High Resolution]
Raster/Vector Balance:
Set the slider to 100
Line Art and Text resolution:
Set this to 1200 ppi
Gradient and mesh Resolution:
Set this to 300 ppi
Convert All Text to Outlines
Uncheck this selection.
Convert All Strokes to Outlines:
Uncheck this selection.
Clip Complex Regions:
This will be inactive.
Preserve Overprint
Check this selection ON.
Page-Level Transparency Blending Color Space
If nothing is active, select Device CMYK
Apply to PDF
Select All pages in document.
When all of your settings are ready, press the “Apply” button. Acrobat will now flatten your file.
At this point, preview your file to be sure no elements were dropped out when flattening.
See page 5 for examples of elements dropping out.
Transparency Flattening in Acrobat Professional 3
Step 2 - Flattening your PDF - Acrobat X Pro
With the Flattener Preview window open, make sure the following
settings are applied:
Highlight Transparent Objects
This will highlight any element that has
transparency applied to it. If the entire page is
affected, it will all be highlighted in red.
Preset:
Set this to [High Resolution]
Raster/Vector Balance:
Set the slider to 100
Line Art and Text resolution:
Set this to 1200 ppi
Gradient and mesh Resolution:
Set this to 300 ppi
Convert All Text to Outlines
Uncheck this selection.
Clip Complex Regions:
This will be inactive.
Preserve Overprint
Check this selection ON.
Page-Level Transparency
Blending Color Space
If nothing is active, select Device CMYK
Compression Settings For
Flattener-Generated Images:
Set Monochrome to CCITT Group 4
Set Grayscale: ZIP
Set Color: JPEG Quality: Maximum
Apply to PDF
Select All pages in document.
Convert All Strokes to Outlines:
Uncheck this selection.
When all of your settings are ready, press the “Apply” button. Acrobat will now flatten your file.
At this point, preview your file to be sure no elements were dropped out when flattening.
See page 5 for examples of elements dropping out.
4 Transparency Flattening in Acrobat Professional
Step 3 - Spot Colors causing unintended overprint errors.
In the screenshot shown above, while looking at the “Output Preview” of the page you will notice that
“Simulate Overprinting” is checked on. This setting attempts to simulate the appearance of the print
PDF on screen to your monitor. When this setting is toggled on and off, this will give you a preview of
any elements that will drop out if they flattened with transparent elements. Spot colors if not converted
to process colors before flattening will cause the graphic to knock out the underlying colors. This is
illustrated in the screenshot below.
In this case, the spot color knocks out the underlying process colors. This will be reproduced incorrectly
in the printed product. The file should be corrected in the original layout document making sure that the
spot color swatches are converted to process colors before exporting your PDF.
Transparency Flattening in Acrobat Professional 5
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