Many publishers seem to have forgotten the importance of rhythm. Rhythm is essential for making books easy to read and for encouraging “immersion”–that is, the magical one-to-one communion between author and reader when time is forgotten and the reader’s entire attention is focused on the book.

All too often today’s books are cluttered with visual distractions that make rhythmic reading impossible. These distractions take many forms–oversized subheads, gratuitous quotations, numerous icons (tips and warnings), oversized pull-quotes, frequent sidebars, and the decorative–as opposed to functional–use of colored background panels.

Although these tools may have played an important role in the original success of several high-profile computer book series, the techniques have spread to other areas–especially business books. Now they’re becoming so overused that publishers may be alienating their readers.

Curiously, this widespread abandonment of the basics of design and typographic excellence coincides with the success of beautifully designed books like Sebastian Junger’s The Perfect Storm and Malcolm Glackwell’s The Tipping Point.

Get the Message?

Reading is an unconscious but incredibly complex event. As you’re reading this, for example, you’re not “sounding out” each word. Rather, your eyes are scanning the patterns, or shapes, of the words on each line while your brain is simultaneously translating the word shapes into an understandable message.

When line length, type size, and line spacing are consistent and correct, and when the typeface is right, this “translation” occurs instantaneously without conscious effort on the reader’s part.

Reading is easy when there are few, if any, interruptions to the rhythmic left-to-right scanning process. Reading is hard when there are frequent changes in type size, line length, or line spacing. Rhythmic reading is impossible in the presence of frequent text wraps, which occur when text or graphic elements extend into an adjacent columnreducing line length.

If we want to continue to attract readers and publish books that offer long-lasting pleasure and value, we must design them so that they help their readers establish and maintain an even reading pace. This pace, or rhythm, is based on repeated left-to-right eye movements of equal length.

The Starting Point

Rhythmic reading begins when designers make basic formatting decisions correctly:

• Type size must permit readers to scan several words at a time.

• Line length must remain consistent.

• Line spacing (also referred to as “leading” or “white space between the lines”) must help words stand out and guide the reader’s eyes across each line.

Type size, line length, and line spacing form the “holy trinity” of rhythmic reading. All three must be in harmony with each other for rhythmic reading to take place. Long lines of small type are hard to read; so are short lines of large type. Likewise, too much or too little line spacing seriously interferes with rhythmic reading.

Although designers have long recognized that it’s impossible to consider type size without simultaneously considering line length and line spacing, too many books that appear today contain columns “bloated” with oversized text. These may, on the surface, appear easy-to-read, but reading them is actually more difficult because the type size is too large to be comfortably scanned.

However type size, line length, and line spacing aren’t the whole story. Decisions about them can’t be isolated from the designer’s choice of typeface.

Typeface Choices

Serif typeface designs, like Garamond, Minion, or Times Roman, further encourage rhythmic reading. The serifs, or tiny strokes at the ends of each letter, give each character a unique shape and guide the reader’s eyes from word to word.

Sans serif typefaces, like Arial, Frutiger and Gill Sans, have less recognizable character shapes. In addition, their x-height–the height (or body) of lower case letters like a, e, o, and u–appears significantly larger than that of serif typefaces set the same size.

The higher x-height of sans serif typefaces has several implications. One is that sans serif typefaces typically require more line spacing than serif typefaces–although this lesson appears to be frequently forgotten. Another is that ascenders (portions of “tall” letters like b, d, and l) are not as prominent as on serif typefaces. Likewise, descenders (the “dropped” portions of characters like g, p, and y) are not as prominent as on serif typefaces. This reduces rhythmic reading because the shallower ascenders and descenders make word shapes harder to recognize.

Although the advantages of serif typefaces are evident, many books are set in insufficiently leaded sans serif type. The problems this creates for reading are compounded when there are frequent text wraps. And when text wraps reduce column width to just two or three words, rhythmic reading becomes impossible.

Why Take a Chance?

Every time you introduce a change that interrupts your reader’s consistent, smooth, and rhythmic left-to-right eye movement, you raise the possibility that the reader will put down your book–and, possibly, never pick it up again.

For this reason, avoid unnecessary changes in type size, line length, or line spacing. Instead, make it as easy as possible for readers to establish a consistent rhythm (similar to the pace you’re most comfortable at while jogging). And avoid text wraps whenever possible.

To Learn More

The fact that readers “scan and recognize” rather than “sound out” words has many implications.

If you’re a Windows user interested in learning more about rhythmic reading, visit the Microsoft Web site and download the Microsoft E-Book Reader. You can download version 2 of the Microsoft E-Book Reader for free at www.Microsoft.com/reader.

After you download the Microsoft E-Book Reader, download Bill Hill’s free e-book, “The Magic of Reading.” You’ll find a full discussion of the miracle of rhythmic reading (called “serial pattern recognition”) plus descriptions of the results of decades of research on the miracle of reading. Also, you’ll find numerous tips and techniques to help you design easier-to-read books, plus suggestions for further reading.

Roger C. Parker is President of Guerrilla Marketing Design, Dover, New Hampshire (www.GmarketingDesign.com). Over a million and a half readers own copies of the 24 books he’s written, translated into 37 languages. His first book was “Looking Good in Print,” which The New York Times called “The one to buy when you’re only buying one.”