A few timely words about a most humble and hardworking typographic symbol

The dash – also known somewhat incorrectly as a hyphen – is a hardworking part of every typographers and typists toolbox. Being so ubiquitous it’s also misused quite a bit, mostly because of a simple lack of information. And, just as texts on desktop typesetting seem replete with reminders that two spaces after a period are unnecessary, questions seem to endlessly arise about usage of the dash.

Here, then, is a short primer about the most common dashes, and how to use them.

A brief dash bestiary

An intriguing thing to find, once one is introduced to typography, whether or not one comes from a typists’ background, is that there are a handful of different forms of the dash.

There are two essential forms of dash to be aware of, if one must state the very obvious, and exclusive of the standard hyphen available on the computer keyboard:

• The shorter of the two is about the width of the standard minuscule “n”, and is predictably called the en-dash. The typical Mac keyboard access is Opt-minus, for Windows hold down the Alt key and type 0150 on the numeric keypad.
• The longer of the two is about the width of the standard minuscule “m”, and is just as predictably called the em-dash. For the Mac, Shift-Opt-minus, for Windows, hold down Alt then type 0151 on the numeric keypad.

The diacritic known as a tilde (~), when used as a dash, is also called a swung dash. There is also a dash of intermedite length – the three-to-em (M/3) dash – that is, of course, one-third of an em-dash. Other forms of dash may be available, depending on the application or the character set.

How to use them

Given the history of desktop typesetting, some good typing habits have been brought forward into bad desktop typesetting habits. As the habit of putting two spaces after every period must be broken, so must the typist’s habit of indicating a long dash with a double hyphen (--).

In type, dashes serve a variety of needs. This most common of these is setting off a different phrase within a sentence – just as I’ve just done here. There are also dashes that weld two words together in a single term (such as the dash in the term one-third), An individual typesetter’s use is sometimes guided by habit and training.

Bringhurst, in The Elements of Typographic Style, offers the following guidelines:

• Use spaced en dashes – rather than double-hyphens or em dashes – to set off phrases.
• Use close-set en dashes or M/3 dashes (which can be formed by shortening an en dash if not available in the type set) to indicate ranges. In this wise, the dash stands in for the word to.
• If used, a good use of em dashes is to introduce speakers in a narrative dialogue. This is inspired by the European style, and is less fussy than quotation marks:

  —Did they want us to stop there?
  —No, they wanted us to move along.

Why should we care?

One of the hallmarks of designing is using tools with knowledge and intention. A designer, and especially a typographer, is aware that there are different types of dashes and they have specific meanings. Using them properly contributes to the professional finish that a true professional strives for.

More than that, simply using a default of what the computer supplies when one knows better has the effect of essentially allowing the computer to design for us. Even the smallest bit of type communicates, and improperly used type can obscure communication. People will notice, even if they don’t realize they are.