A lot of our clients are moving to PDF-only publishing for at least some of their documents, if not all. But there's more to digital publishing than hitting the "save" button. PDF documents offer many opportunities for an enhanced user experience—and a few pitfalls—that you might not be aware of.

1. Prefer landscape to portrait

Historically, books are bound along the tall side so they're more comfortable to hold open. But look what happens to that 8.5 x 11" publication when you view it on screen. To see the whole page, you have to reduce the magnification, making it harder to read. Monitors today are wider than they are tall. Check out my landscape example—the same page size set to horizontal fills the screen and is much easier to read.

Portrait pages are an inefficient use of on-screen space:

Landscape pages are easier to read on screen:

2. Abandon the "facing page" mentality

In conventional publishing, we are used to seeing the right and left sides of the page at once. Conventions have sprung up to create symmetry across the two-page spread—placing page numbers to the outside, for example, or creating a wider center margin to accommodate the binding. In PDF printing there are no right and left pages. Layouts should be designed as if the publication was to be stapled in the corner—even left and right margins, and consistent placement of page numbers, headers, and footers on every page.

Facing page design doesn't make sense when readers are only seeing one page at a time:

3. Make use of color

In digital publishing, color is free. If you've had to settle for black and white pictures and two-color printing in your paper documents, PDF publishing frees you from those constraints. This isn't to say you should start making every heading a different color. But think about using color photographs, adding color to tables and charts, and incorporating more visuals in general.

4. Add links

Readers expect website addresses in digital documents to be links. In Acrobat, the cursor will change from an arrow to a hand when it passes over a linked area. But I like to provide an additional visual cue to indicate links, usually a highlight color for the type. You could also underline links, but in close-set type this can create unnecessary clutter. Add links in your PDF by going to Tools > Advanced Editing > Link Tool.

A different link color reinforces their clickability:

Draw a box around the link to create a "hot" spot and specify how you want the link to appear to the viewer. For a seamless reading experience, I prefer "Invisible Rectangle" and "None" for the highlight style. Many layout programs, including Adobe InDesign and Microsoft Word, will carry over links you've created into the PDF document, which saves time.

How to choose your link options:

5. Create navigation and wayfinding

Not only can you add links to websites, but you can create internal links to help readers navigate your document. The obvious place to start is your table of contents. Next, scan your document for internal callouts to pages, figures, and tables.

Another approach is to create "persistent" navigation that is visible on every page of the document, similar to what you find on websites. Since this is a design element, persistent navigation must be created in your source document (it can't be added in Acrobat) and can take away space from your content. A good use of persistent navigation is in annual reports, where readers often want to skip to the financials or the CEO's letter quickly. Just as on the web, it's important to use signposting in the navigation so people know what section they're in. In the example below, the current section is highlighted in orange.

Persistent navigation should be big enough to read and select easily:

6. Consider embedding rich media

Acrobat allows you to embed rich media such as Flash animation, movies, and audio clips. Because Acrobat natively imports the Flash .swf format, you can embed interactive slideshows, animated charts and graphics, or anything else you can dream up. Those same Flash files can do double-duty on your website.

An important consideration when embedding rich media is that the larger the file size of the embedded content, the larger your PDF will be. Based on our tests, embedding a 6MB movie also increases the PDF file size by 6MB. An alternative is to house your rich media content online and use a URL to call it up.

Download the example file above to see the difference between embedding and linking (you'll need Acrobat 9 to see the video). It takes a while to download the 12.7MB file, but the embedded video on the left plays instantly. By contrast, the linked video on the right makes you wait after you've clicked and, unfortunately, Acrobat doesn't provide a progress bar graphic. Instead, I created a "poster" image with a message alerting the reader about the wait time. If you don't use a poster, the default image is an ugly grey box.

7. Know your audience

Jazzing up your PDF with pictures and video is more appropriate for promotional publishing like sell-sheets, annual reports, brochures, and press kits. If your readers are primarily after the content, you may get better results with a text document or eBook file they can read on their Kindle or iPad. If you think the majority of readers will be printing your document, you may want to eschew persistent navigation since it takes up space on every page. Additionally, readers may not have the latest version of Acrobat Reader or the Flash player that are necessary to view your file properly.

8. Beware of font licensing

Last, but by no means least, check the licensing agreement for all fonts embedded in your PDF file. Not all licenses are created equal. For example, some of Adobe's fonts are licensed for embedding and editing and some are licensed for previewing and printing only (see their list). Other foundries (e.g., Hoefler & Frere Jones) may require you to buy a separate license to embed their fonts in publicly distributed PDFs. While font foundries don't have the resources to chase down every license infringement, last year's $2 million suit brought by Font Bureau against NBC might give you cause to check your licensing agreements.

All this and much, much more!

These suggestions are only the tip of the iceberg of what's possible with PDF documents. Because PDF was conceived as a file-sharing platform, it includes all kinds of sophisticated features—encryption and security, embedded forms, javascript, geospatial mapping, commenting, version tracking, and probably a hundred other uses I'm not aware of. For simple one-way publishing, however, this article should put you well ahead of the game.

[ Kim Bieler wrote this article and she welcomes your comments. ]