How To: Proofing with layered PDFs can ease and speed the review and revision process.Since Acrobat 6, PDFs have been capable of holding multiple pages of information in the same space through the use of Optional Content Groups—more commonly known as layers.
Layers in PDFs are just like layers in InDesign and QuarkXPress and like top level layers in Illustrator and Photoshop.
Each layer may hold any portion of the document's objects, and layers may be made visible or invisible, showing or hiding their contained objects, in any combination.
As a creative, you use layers to organize and separate elements of a design. While sketching and refining a Web site design in Illustrator, for example, you may divide background imagery, main content areas, sidebars, FPO objects, header and footer, and advertisements amongst their own top-level layers.
A print layout in InDesign might place overlapping content on locked layers to prevent accidental repositioning.
By selectively hiding layers, you reduce distractions to concentrate on particular areas or types of objects.
You also employ layers to facilitate experimentation and variations on a design—common objects are stored on a lower layer, with alternate versions of other elements on upper layers.
Layers infuse numerous creative and productive benefits, and, in most cases, the same benefits can be afforded to the client during review.
Using layered PDF proofs, clients can peel away FPOs or advertisements from their Web site comps; by hiding all but a specific layer or two, they can isolate a design's copy or photography from its other elements, evaluating each type of content individually, and; variations to the design can be presented and compared like overlaid transparencies without the increased file size or disarray of managing multiple pages or files.
One of the most powerful uses of layered PDF proofs is in multi-lingual designs such as my ad for REVdrink.com, which contains a single set of common graphical elements but five versions of the copy.
Naturally, the ad was designed on a single page in InDesign using layers. When sent for review and markup as a layered PDF, the client simply toggled the layers to see the English, Spanish, Italian, German, and French copy in place.
Comments and markups related to the design were confined to a single page (which made it easier for me when altering the design), and proofreaders isolated their respective languages from the background and product imagery.
Proofing this ad in layers also saved me time and hassle (and my client cost). Without layers, I would have had to turn on one language layer at a time and then export to PDF.
Then, once all five PDFs had been generated, I would have had to combine them in Acrobat. While only a 10-minute process, it would be 10 minutes for each design revision, each copy proof, each variation…
Creating Layered PDFs
Acrobat isn't a layout application, so you can't create layers within Acrobat itself without a third-party plug-in like ARTS PDF Stratify.
Instead, create layers at PDF generation time in your design application. Adobe Illustrator and InDesign can create layered PDFs natively, without Acrobat installed, and AutoCAD and Visio can do it with Acrobat's PDFMaker plug-in.
Within InDesign's Export Adobe PDF dialog box, on the General pane, you can create layered PDFs by setting the Set Compatibility to either Acrobat 6 (PDF 1.5) or Acrobat 7 (PDF 1.6) and checking Create Acrobat Layers in the Options section.
A warning will inform you that, if your layered PDF is viewed in versions of Acrobat or Reader earlier than 6.0, all objects, on all layers, will be visible simultaneously.
Illustrator CS & CS2 save rather than export PDFs. Choose File > Save As (or Save A Copy) and, from the Save dialog, set the file type to Adobe PDF.
After specifying the location and file name, the Save Adobe PDF dialog will pop up.
Choose either Acrobat 6 (PDF 1.5) or Acrobat 7 (PDF 1.6) from the Compatibility dropdown, and then check Create Acrobat Layers from Top-Level Layers.
Enabling Layered PDFs
When opening a PDF containing layers, a Document Status alert notifies the user (with an iconic rendition of a slice of layered cake) of the presence of layers, and provides basic instruction for accessing them.
Few users notice and actually read the alert, however, and fewer still learn enough from it to make use of the document's layers.
Instead of banking that clients will notice and understand the underwhelming alert, I prefer to embed a more obvious and useful instruction layer atop my design proofs.
Through its 90 percent opacity background, clients see their befogged designs—instantly recognizing the purpose of the PDF—but are forced to read, comprehend, and follow the brief instructions in order to see their projects clearly.
The instruction layer object, stored in a global symbol library for Illustrator and in InDesign as a snippet, is simple direction even the most technologically challenged client can follow.
Just before generating the PDF proof, I add to the top of the document's Layers palette a new "INSTRUCTIONS" layer containing the symbol or snippet. This, in turn, becomes an easily disabled layer in the PDF.
Also, because the Layers pane is hidden by default in both Acrobat and Adobe Reader, give your clients an extra helping hand by forcing the Layers pane to display with layered PDFs.
To make the Layers pane display for your clients, open the layered PDF in Acrobat. Choose File > Document Properties, and, on the Initial View tab, set the Show option to Layers Panel and Page. Click OK and save your PDF.
You can afford to your client during review and revision nearly all the advantages you derive from using layers in design applications, and the benefits will come back to you in reduced work and time to generate PDFs, as well as when making changes after client review.
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