For Position Only: Designing PDF E-Books, Part 1
Ah, e-books. The term buzzes in my ears louder than a horsefly. The technology has been riding tumultuous waves lately, with continuing news of e-book-centric dot-coms folding (such as MightyWords and iPublish) yet reports of exponentially growing numbers of e-books being downloaded from the Web. And of course, e-books were also a hot topic at last month’s Seybold Seminars in New York, where e-books were an integral thread of discussions on interactive content, wireless publishing, and digital rights management.
While e-books have yet be a source of big bucks for most publishers or technology vendors, no one is betting on their future more than Adobe, and specifically, with Adobe Acrobat. With its left hand the company is wheeling and dealing to buy or ally with critical technology partners; with its right it’s adding capabilities to Acrobat and other products to make the e-book experience not just functional but optimal for your reading enjoyment.
I’m not going to advise you on the business merits (or demerits) of e-book publishing, but should you be considering taking the e-book plunge, here is the first of a two-part column on how to design them well.
Go PDF
For e-books you need PDF. Sure, you could use XML instead, but XML is a mark-up language, a means of describing data in a text file. It’s all about organizing and adding structure to content, but when you design using mark-up languages you by definition cede control over how the final piece will be displayed.
While there are lots of good uses for XML, such as when you need content to be searchable, extractable, and portable (for viewing on multiple devices), PDF is about pages, just like book pages whether printed or electronic. PDF files describe elements on a page, preserving original design intentions and placing form above function. Readers approach e-books with many of the same expectations of printed books, so PDF provides a high level of comfort for readers, especially while the medium is still new. And for anyone already used to the page-layout metaphor and Adobe applications in general, it’s a straightforward process to design your book (almost) as if it were a print publication, and then save it as PDF.
Use PageMaker or InDesign
There is one important reason why you should use PageMaker or InDesign as your design applications: They both offer an Export PDF command. This command will make your life easier in two ways. First, it maintains the custom page size that you specify for your e-book (more on that in “Optimize Your Design”), whereas printing to Distiller may require you to crop the pages in Acrobat. That’s because Distiller creates pages based on what’s specified in your Page Setup. (Actually, while InDesign uses libraries to create the PDF files, PageMaker does go through Distiller but still allows you to maintain your publication’s page size.)
But more importantly, when you export PDF from PageMaker 7.0.1 and InDesign 2.0, Acrobat lets you create structured, tagged PDF files. These tap into some of the strengths of XML. Tagged, structured PDF files recognize the hierarchy of information in the document, such as what’s designated a header and what’s body text, and even how text is formatted within a table. As a result, tagged PDF files can be reflowed onscreen in Acrobat 5.0, Acrobat Reader, Reader for the Palm, and Acrobat Reader for Pocket PC, preserving the logical reading order now matter how the page window is sized.
Optimize Your Design
When you set out to design e-books, keep in mind that your audience will be reading the content onscreen and set up the document appropriately. First, make a fairly small page size, such as 7 x 10 or 6 x 9 inches. This will display on both desktop PCs, to which readers might download the book, and on many handheld devices, where they might actually read it. If you know your e-book will only be viewed on a computer monitor and won’t be printed, consider making it 640 x 480 pixels (landscape orientation) for viewing on 15-inch or smaller monitors, or 800 x 600 pixels for viewing on 17-inch or larger monitors.
Also, since e-books aren’t printed and bound, you don’t need to specify double-sided, facing pages. By the same token, you can make margins uniform on all sides. However, don’t chintz on resolution: Make it 300 dpi so that text and graphics will be sharp even when downsampled and compressed.
Another layout guideline is to create single-column pages. Multiple columns don’t work well in e-books, because they force readers to scroll uncomfortably. For body text, use at least 12-point type and at least 2 points of leading: This will make the text more legible and readable onscreen. Similarly, avoid delicate serifs and thinly stroked typefaces, but do use solid tints is you color your type. Your readers, especially those over 40, will appreciate it. Finally, don’t waste undue time on kerning individual letter pairs, which don’t significantly improve onscreen readability but do add to file size. Rather, set wider tracking values globally.
As for graphics and images, spec your colors in sRGB, the standard Web color model. Not only does color look differently on different computer monitors but it varies on various handheld devices. sRGB levels the playing field a bit. Think carefully about the size, number, and types of graphics and images you want to include. They add a lot of weight to the file and their positioning can affect the flow of the text, so be sure they add enough value for the reader.
Export the File
When your e-book has been beautifully laid out, it’s time to save it as PDF. Choose File > Export from either PageMaker or InDesign. The Export process and dialog boxes vary, but choose Adobe PDF as the type of file you want to generate, and be sure to check the Embed or Include e-book tags box. Use eBook as your Distiller job option or style, which applies a suitable amount of compression and embeds and subsets all but the Base 14 fonts, or customize the setting to include those fonts as well.
If you’ve created hyperlinks and bookmarks in your page layout file, such as from tables of contents and indexes to the relevant chapter or discussion in the text, you can opt to include those in your exported PDF as well. Such navigational elements are essential to e-books, making the reading experience much more fluid and accessible in the online medium. But I’m out of space for this column, so I’ll pick up here next time, showing you how your structured and tagged PDF will reflow, as well as how to add navigational elements in Acrobat.
This article was last modified on January 8, 2023
This article was first published on March 7, 2002
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