Basic Book Design/Justification
Keep Out Of Trouble Rules
Use justified paragraphs.
Justiﬁed text has even left and right margins. Unjustiﬁed text has an even left margin and a "ragged right" margin.
This paragraph is justiﬁed. This sentence is in a justiﬁed paragraph. This sentence is also in a justiﬁed paragraph. This sentence is—you guessed it!—also in a justiﬁed paragraph.
This paragraph is ragged right. This sen-tence is in a ragged right paragraph. This sentence is also in a ragged right para-graph. This sentence is—you guessed it!—also in a ragged right paragraph.
Typeset books use justiﬁed text. Justified text looks nicer. Readers are used to reading justiﬁed text, so justiﬁed text is easier to read.
"Ragged right" text improves retention. I.e., if you want readers to remember what you wrote, and especially to return and ﬁnd items they'd read earlier, use of "ragged right" may be justified (sorry, I couldn't resist the pun). Just as readers recognize words by their shape, they also remember ideas by the shape of the paragraph.
"Ragged right" text should be used in one other situation. If the column is very narrow, or the font size is very big, or the words are very long (e.g., website URLs), justified text can produce huge white spaces between words, called open lines. Open lines are a sign of amateur typesetting.
Instead, set a website URL centered on its own line. If you're forced to use a narrow column (e.g., ﬂowing text around an illustra-tion), look at it both justiﬁed and "ragged right," and choose what looks best.
Text is always justiﬁed by increasing white space between words, never between letters within words. The latter (called letterspacing) would make word shapes difﬁcult to recognize. Text should always be justified by adding equal amounts of space between all words on a line. Early word processors (in the 1980s) put two spaces between some words and one space between other words. That looked awful.