Acrobat How-to: Softproofing PDFs with Acrobat's Preflight Tools

John Clifford

While preflight is usually the bailiwick of prepress houses sending files to printers, there are a number of things that can be used for softproofing files. One of the biggest concerns of users of Acrobat for printing is (all together now) transparency. So how do you know if there is transparency in your PDFs at an early enough stage so that you have time to fix them if needed? At your softproofing stage you can turn to the preflight tool built into Acrobat 6 Professional and simply ask it. Go to Document > Preflight then select a profile, in this case List all transparent objects:

Clicking the Analyze button will return a list of all transparent objects and what page they are on.
As you can see from the list of profiles, you can also check for such things as Output predictability (this is great for someone who has little or no experience with preflight settings), all compressed images, and the number of printer plates that a file would have. Of course, for the professional, there are also profiles for ensuring that files conform to PDF/X versions, as well as tools for ensuring PDF/X conformity in an automated process.
Proofing Press-Ready PDFs
In addition to the tools available for traditional proofreading of text, page geometry, and simple color breaks, Acrobat 6 Professional also offers the professional prepress house tools for proofing overprints and color separations.
Overprints can cause major problems if not caught at the proof stage. Acrobat, in both Acrobat 5 and 6, offers an “overprint preview” option from which you can view or print proofs to show how overprint settings will affect a file. Find it under Advanced > Overprint Preview.
Here is an example of a file with an overprint problem:

This image is how the page traditionally proofs when the show overprint option is not activated.

This is the same image with overprint preview selected. Notice that there was some text on the master page. While this text was covered by the blue box, when black was set to overprint, it overprinted that blue box and showed up on the page — a very costly error if it had gone to press this way.
Another way to look at pages to see if they are print-production viable is to use Acrobat 6 Professional’s built-in separation preview (Advanced > Separation Preview). In Separation Preview, this same page can be seen in its component plates.

Within the separations panel, we see that in this instance the job has CMYK plates as well as a spot color plate for Pantone 314 CVU. Immediately, if we didn’t want a spot color, we would see that we had too many plates. By clicking once on the check box next to the spot color, it will turn it into its CMYK formula:

Clicking the check box a second time turns the spot color off:

You can, of course, also look at individual color plates to verify what information is carried on each plate. This will show up things such as rules with three or more colors, black showing up on all plates (rich black), or other problems with color separations.

This map shows CMY without the black plate.

The same map showing only the black plate.
Conclusion
Adobe has built some great functionality into Acrobat 6 Professional for those who have to create a softproof workflow. PDF files can now be fully preflighted and tested right in Acrobat. New markup tools and proof printing tools allow you to integrate softproofing into the mainstream workflows without having to deal with “foreign” looking marks. And Adobe has promised even more tools in future releases of Acrobat Professional.
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