Persuasive Advertising - J. Scott Armstrong [183]
Reverse print slows readers. Starch (1914), in an experiment using 40 subjects, found that a light font on a dark background reduced reading speed by 42 percent. Wheildon (1995, pp. 97–9) tested reverse print using 224 subjects, each of whom read a long message. He reported much better comprehension for those who read “black on white,” than for those who read the same passages with “white on black.”
Shading slows readers. As with reverse print, it should be used only for small sections of an ad. Light shading, when used sparingly, is useful as an attention-getting device. However, shading might harm comprehension. Wheildon (1995, p. 97) found that shading beyond 10 percent (10 percent is shown above) reduced comprehension when used for large blocks of text. He reported large drops in comprehension as shading increased to 30 percent.
In Wheildon’s (1995, p. 77–102) experiments, most subjects found color fonts to be attractive and black to be boring; however, their comprehension was better when a black font was used.
9.5.3. Avoid uppercase and bold font for informative text with three or more lines
Readability suffers when all capitals or bold are used for text that extends three or more lines. This is especially important for high-involvement products with good arguments. Note that this does not apply to normal headlines. Headlines are typically in bold, and that is a proper way to call for attention.
Capitals require more space. Based on a small sample, I found that capitals require about 30 percent more space.3 Thus, avoiding capitals can provide substantial savings in media costs. Bold does not need so much space; my small sample estimate indicated that it needs about 4 percent more.
Advertisers often use bold or capitals for low-involvement purchases to gain attention or to add an emotional dimension. It can sometimes improve legibility, such as for STOP or DANGER! Thus, it is useful for billboards and signage.
Bold and especially capitals are analogous to shouting. They distract a consumer who is considering a high-involvement purchase. Consider how you would feel if a salesperson screamed BUY THIS CAR.
Advertisers sometimes use capitals to announce defects or limitations in products, such as “FAILURE TO COMPLETE THIS [GOVERNMENT] FORM PROPERLY WILL LEAD TO PENALTIES OF $100 PER DAY.” While it looks like the ad is adding emphasis, the reality is that consumers will be less likely to read or correctly understand it.
Evidence on the effects of capitals and bold
A study using 40 readers found that when all letters were capitalized in long text, reading speed was 10 percent slower than when lower-case letters were used (Starch 1914).
Our quasi-experimental analyses found that bold aided recall when used in headlines, but it harmed recall when used for three or more lines in the text:
Print ads with bold headlines had higher recall. Our WAPB analysis found 33 pairs of print ads in which one ad used bold font in its headline while the second did not. Recall of ads with bold headlines was 1.14 times better than for the other ads.
Print ads for high-involvement products with strong arguments had higher recall when they avoided bold font for the text. Our WAPB analysis found 12 pairs of print ads for high-involvement products with strong arguments, in which one ad used bold font for text (of at least three lines) while the second did not. Recall of ads with regular font was 1.16 times better.
Wheildon (1995) presented subjects with passages using either all capital letters or all lowercase letters. Across five different fonts, subjects rated lowercase type as much easier to read than capitals.
Bold fonts seem harsh. In a study using on-screen text, a bold-looking font, Impact, was ranked first of 19 fonts in terms of being assertive, rigid,