Why space-space is a no no

Question: I’ve been having problems trying to convince my friends why it’s wrong to type two spaces after a period. They just say that it’s what they’ve been taught to do, so that’s why they do it! Can you tell me (and them) why it’s never done?

Answer: It’s true, we often see the "warning" against double word spaces, but never with a reason why. Well, here it is:

When a typewriter (the old-fashioned kind) types a letter, the carriage moves ahead by a set increment in preparation for typing the next letter. This increment is always the same. This means that typewriter typefaces have to be designed so that all the characters occupy the same amount of space on the line. These are so-called monospaced typefaces. In mechanical terms, you would say all of their letters have the same "escapement," which is the distance the typewriter mechanism moves. In computer terms, you would say that they all have the same "character width." Creating monospaced typefaces calls for characters that have unnatural proportions. Wide characters can be squeezed, but narrow characters can only be designed to be so wide, so many of them (especially punctuation) have a lot of white space on either side of them.



Look at the samples above. In a monospaced typeface such as Courier (top), the shapes of some characters have to be "stretched" to approach having the same widths as all the others. Similarly stretching the widths of the characters of Times Roman (middle) shows the distortion needed when compared with the normal typeface (bottom).

The overall effect of this kind of typeface design is that the type you set using them looks very loosely spaced on the page. Thus the point: If you use only one word space at the end of a typewritten sentence, it’s not wide enough to make an appreciable gap between one sentence and the one that follows it. This gap is a visual cue that you’re transitioning from one sentence to the next, and if the space is too small, this cue just doesn’t do its job.

More concisely put, double word spaces between typewritten sentences help to make the type look more naturally spaced and to read more easily.

Typesetting systems, on the other hand, use proportionally spaced typefaces, where the width of each character can be customized to accommodate the natural shapes of the letters (and not vice versa). When this happens, type sets more tightly, which makes word spaces stand out more. A result is that one word space after a sentence is sufficient to provide that visual cue. Two spaces simply look too wide.

So ultimately it’s an issue of aesthetics and readability. The best solution on a typewriter is two spaces between sentences, but on desktop publishing systems (i.e. "word processors"), the best solution is just one space.

NOTE: Even Microsoft Word, the world's most common word processing program, is designed to automatically change two spaces between words to one space. (Many people turn this option OFF, however. Probably because "old habits are hard to break.") To view this setting in Word 2000, for example, click on "Tools" then on "Options." Under "Writing style," click on "Settings..." Set the "Spaces required between sentences" to "1" (one).