With these four rules you can ensure that your fonts do what matters: Help your readers find what they’re looking for in your document. Picking the right fonts for your documents doesn’t have to be like a wine tasting event.
I know that discussing fonts can start to sound like a snob at a wine tasting property ( “This font has an indigent taste with crepuscular overtones, but I think you’ll appreciate its effrontery”). Don’t Panic! As we discuss in Learning Tree’s Technical Writing course, picking the right fonts to support your readers is much simpler than picking the right wine for dessert. Trust me.
Picking the right font matters because it has a direct impact on your readers’ ability to read your document.
First: You need to make sure your font is big enough. For adults, you can go as small as a 10-point font without impacting their reading speed. However, older readers prefer larger fonts, which means that 12-point is probably your safest choice, unless you’re sure that all of your readers are under 50 years old.
Second: After getting the size right, you need to consider the kind of font you should use. There is some debate over whether the kind of font you choose has an impact on your readers. The answer seems to be that, if the type of font does make any difference at all in reading speed, then you should use a serif font…on paper, at any rate (a serif font is one like Times New Roman that has those little ‘wingies’ at the end of the lines that form the characters).
If your readers will reading your document on a tablet or a computer screen, the question is more complicated. On most screens, if your font is 12-points or less, the little ‘wingies’ in a serif font disintegrate into a random collection of pixels that reduce legibility and make your text harder to read. So, on the web, you should use a sans-serif font (sans-serif fonts, like Helvetica, don’t have those wingies at the end of their lines) unless you’re going to use a large font (16-points or larger)…or can count on your readers using some high definition device like the iPad’s Retina display.
Now that you’ve picked the size and type of font for the text of the document/site, you’ll need to consider what font to use for your headings. The key to that decision is to recognize that your readers don’t read your articles from start to finish. Instead, readers scan your document to find the chunk of information that they want. In an earlier post, I discussed how you can make those chunks immediately visible to your readers as soon as they look at your page. But, while that’s a good first step, you also need to identify the content of each chunk so that readers can find the chunks they want.
Your chief tool for telling your readers what your chunks contains are your section headings. However, for those headings to be useful when a reader is scanning your document you have to ensure that your headings stand out from the rest of your document. Unfortunately, the advice that I gave in that previous post on defining chunks tends to make your headings harder for your readers to see. But this is where picking the right font matters. Effective use of fonts can make your headings stand out, provided you use a font for your headings that’s as different as possible from the font you’re using for your content.
Third: To achieve that difference, begin by making your headings larger than your content. In order for the human eye to be sure of a difference in font size, your heading should be at least 33% larger than your content font. For example, if your content is in a 12-point font then your headings should be in 16-point (12 * 1.33 = 16).
Fourth (and finally): Leverage other differences between fonts to make your headings stand out. If your content font is a serif font (as it should be on paper) then use a sans-serif font for your headings. If your content font is a sans-serif font (for a 12-point or less font on a computer screen) then make your heading a serif font. If you look closely at the letters in your content font, notice whether the various lines in the letters vary in their width (this is true of the letters in this blog). If your content font does have varying widths then pick a heading font where widths are more consistent.
Finally, some unnecessary advice: You can also make your fonts different by putting them in different postures (boldface, italic, etc.). Since you were probably going to put your headings in boldface, anyway, you didn’t need that advice. There is, however, one posture you shouldn’t use – don’t underline your headings or put all the letters in upper case. When reading, you recognize words as much by their shape as their letters. The word “shape” for instance has an ascender (the letter ‘h’ that sticks up above the rest of the letters) and a descender (the letter ‘p’ that hangs down below the line) — those ascenders and descenders help you recognize the word ‘shape.’ Underlining or using all uppercase letters disguises the letters’ shapes and makes it harder for readers to recognize words.
To sum up:
And, finally, avoid underlining or putting your headings all in upper case. Following these four rules will give you a document that your users will find readable and, more importantly, where they can quickly find what they’re looking for.