For Position Only: Designing PDF E-Books, Part 2
Editing Structure
Reflowing text is a tremendous advancement in the PDF e-book reading experience, but it’s rather limited, at least for the time being, in how it handles graphics and images. While you may have nicely wrapped your text around an illustration, or carefully placed a graphic next to the text that describes it in your layout, your efforts might be lost in a reflowed PDF page. The graphic might fall to the bottom of the page, for example, and in any case text will no longer wrap.
Acrobat, however, lets you exercise some control over the hierarchy of objects on a tagged PDF page because the file is structured (remember?). Select the TouchUp Order tool and Acrobat displays the elements on the PDF page in numerical sequence. You can just click on the identifying numbers in any order that you desire, and Acrobat updates the page. If an image is the fifth out of five elements on the page, for example, it will be last; but if you make it third, it will appear higher on the page.
If you have the chutzpah, you can actually go in and edit the PDF’s imported XML tags through the Tags palette. Here you can add and redefine tags, find artifacts, and much more, such as adding alternate text to images for visually impaired readers.
Links and Bookmarks
Links and bookmarks are critical to e-book navigation. At the very least, you should link table of contents entries to the first pages of corresponding chapters, and index entries to their corresponding text. If you forgot (or chose not to) create these elements in PageMaker and InDesign and import them with the PDF, you can create them in Acrobat. Just select the Link tool and drag a marquee over the area where the link should originate, such as a chapter page number in a TOC, and when you release the mouse, Acrobat displays the Link Properties box. Define how you want the link to appear (I prefer invisible rectangles) and choose Go to View as your Action Type. Then navigate to the page, whose number will appear in the still-active List Properties dialog box, choose a magnification level, and click Set Link.
Bookmarks are so useful, they’re one of my favorite Acrobat navigational tools. Anytime I open a multipage PDF I’m sorely disappointed if the content creator failed to include them. Bookmarks, which occupy a tabbed pane in the document window or a floating palette, list key locations in a file — such as chapter names or major headers within chapters — and let you jump directly there. You create them by displaying bookmarks and choosing New Bookmark from the Bookmark menu. Type over Untitled to rename this new bookmark, and then choose Bookmark > Bookmark Properties. This dialog box is similar to Link Properties: choose Go to View and navigate to the page you want to associate with the bookmark. Keep in mind that your bookmark magnification level should be the same as it is for your links. (Since you can’t actually specify magnification in the Bookmark Properties dialog box, make sure the page is at the proper view level when you click Set Action.)
Finishing Touches
I’ve just presented the basics here. There’s tons more you can do to enhance navigability and interactivity in PDF-based e-books: create nested bookmarks, for example, and link to movies. But no matter how far you take your e-books, you need to test them extensively. Double and triple check all of navigational elements, for example, to make sure they go to the correct pages, and that pages always display in the same view when a reader lands there. (This magnification level should also apply to your opening page view. To set it, choose File > Document Properties > Open Options, and make your choices. Fit Width is a good option.) Also check out how the PDF reflows on all kinds of devices, and how the book looks on multiple platforms, especially that fonts display properly.
Oh, and did I forget to mention: Have fun.
This article was last modified on January 8, 2023
This article was first published on March 14, 2002
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