The Acrobat.com Blog

There are myriad different opinions on what the best conditions are for reading text on a screen. Debates rage about whether or not to use serif fonts and how long a line of text should be. A surprisingly sensitive issue, and possibly without a clear resolution.ﾠ

Here we’ve tried to delineate a few of the more widely accepted tips on how to optimize readability. Although they can be forsaken in the name of personal style, they’re generally considered the most conducive to easy reading. Here are a few key points plucked from various takes on the subject:ﾠ

1. Regardless of medium, high contrast between type color and page color always contributes to optimal reading conditions. Not surprisingly, readers show a strong preference for black text on a white background (though it’s not strictly necessary; if you simply loathe the combination of white and black, any reasonably contrasting color duo will do). When in doubt, check your color scheme on Snook’s Color Contrast Check.
2. To state the obvious: the more clearly you can see the text, the easier it is to read. This means that the higher the resolution, the better the readability. Printed text is generally of higher resolution, which is why it’s generally easier to read than on-screen text, though high-resolution computer monitors are doggedly pursuing equality, and some are proving worthy adversaries. This has several ramifications:
   • For online reading, sans serif fonts are easier on the eyes (if you need convincing, Alex Poole has put together a compelling argument). This isn’t to say that using Minion (a serif font) will prevent readers from understanding what you’re saying; they’ll just have to work slightly harder to recognize the words on the screen. One possible reason is that on-screen, the resolution isn’t good enough to display crisp serifs; this, in turn, results in letters a little more blurry and slightly less recognizable.
   • Readers of printed text, on the other hand, seem to prefer serifs on their letters (at least in North America—there’s some evidence that Europeans go for sans serif fonts). The argument for this preference, while controversial among the experts, is intuitively appealing: serifs seem to serve as “horizontal cues” that guide the eye along a line of text.
   • A good summary of the two font types can be read here.
3. For the same reason you should consider sans serif fonts for on-screen readability—in the name of crispness—the inter-line spacing within a paragraph should be sufficiently large so that the lines of text don’t start blurring together. If you can, try to keep the ratio of line height (the distance from the bottom of one line to the bottom of another) to font size (the height of a Capital Letter) at 1.5 or so.
4. One more thing about lines: pay attention to their length. The jury is still out on whether or not they should be epically long or reasonably short; conclusive statements from various studies differ, though never drastically (some say 40-80 characters, others say 35-95, and one writer claims that 72 is just right). The take-home point? Don’t go to extremes. Tiny lines of fewer than 10 words and Proustian lines of more than 18 words should be fixed. You can take care of line length issues by playing with font selection, font size, or margin widths.
5. According to Jakob Nielsen, when someone first opens a web page, they’ll decide whether or not to stay after only 20 words. That doesn’t give you much time—maybe a few seconds. So make the most of it: in the initial scan of the page, the reader must be able to extract information about what he’ll find there if he stays and reads it more closely.

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So the next time you’re writing a newsletter (in Buzzword, of course) to share with your band’s groupies, remember this: if you adhere to these general guidelines, your fans will be much more likely to read every single word about how your band’s (only) song got played on the local college radio station last week at 3 AM. No doubt they all stayed awake to hear it; but this way they’ll get to relive the moment as they read the obstacle-free article you send them from beginning to end.
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For the typophiles out there, here are a few recommendations from the Buzzword team for further reading:

1. Bringhurst, Robert: The Elements of Typographic Style — a good modern perspective for a general audience.
2. Tschichold, Jan: The Form of the Book — a seminal historical work.
3. Dowding, Geoffrey: Finer Points in the Spacing and Arrangement of Type — for the real die-hards!ﾠ

Finally, let us know your opinions on these issues! They’re by no means written in stone, and we’d be glad to hear your thoughts. Hit us with ‘em at buzzword@adobe.com.