I have yet to see a good reason for using drop caps (unless it is the year 400, you are creating an illuminated manuscript, and you’re just trying to fit in), but they appear everywhere. Drop caps, where the first letter of a text block is enlarged and “dropped” so that it takes the space of three to five lines of text, violate most of the rules of typographic legibility.
First, in the example above, the individual letters in the word “After” are not the same size, which is poor form in body text. Second, the letters in that word do not share a baseline, which forces the reader to mentally piece together the word rather than reading it fluidly. Third, because of the shape of this particular letter, the drop-cap “A” is actually farther from the “fter” to which it supposedly belongs than it is from “days” in line 2 and “phia” in line 3. Because the “A” is closest to and shares a baseline with “phia” in line 3, it looks like the “A” belongs to the word “Aphia” (there’s a prize for the reader with the best suggested definition of “Aphia”). Readers obviously can figure out which letters belong to which words, but they shouldn’t have to work so hard to do so.
Designers are better served to avoid drop caps and use another method of creating graphic contrast, such as setting the first few words of a text block in small caps, bolding or changing the color of the first few words of a text block, or good, old-fashioned white space.
NOTE: The text in the example above was selected randomly online and just happens to be from the October 30, 2008, Philadelphia Inquirer, reset typographically for the purposes of this post.