What exactly are emdash and endash and what purpose do they serve.
How and why are they important as a part of typography?
Anyone?
Steve
The em dash and en dash are very important. This is an excerpt from Robert Bringhurst’s The Elemnts of Typographic Style, second edition:
5.2.1 Use spaced en dashes rather than em dashees or hyphens to set off phrases.
Stanard computer keyboards and typwriters include only one dash, but a normal font of roman of italic type includes at least three. These are the hyphen and two sizes of long dash: the > en > dash which is one en (half and em, M/2) in width - and the > em > dash which is one em (two ens) wide. Many fonts also include a subtraction sign, which may or may not be the same length and weight as the en dash. And some include a figure dahs (equal to the width of a standard numeral), a > three-quarter em > dash, and a > three-to-em > dash, which is one third of an em (M/3) in length.
5.2.2 Use close-set en dashes or three-to-em dashes between digits to indicate a range.
5.2.3 Use the em dash to introduce speakers in narrative dialogue.
The en dash, followed by a thing space (M/5) or word space, is the normal European method of marking dialogue, and it is much less fussy than quotation marks:
5.2.4 In lists and bibliographies, use a three-em rule when required as a sign of repetition.
An en dash is a solid horizontal line exactly the width of the figure space for the letter ‘n’. In fcp, that is the “advance width” property of the letter ‘n’. An em dash is likewise a line exactly the width of the figure space for the letter ‘m’. A hyphen is often standardized to 1/4 the width of an em dash, but is not always horizontal. Many really well done fonts have hyphens slanted upward as much as 50 degrees. All this information can be found in The Elements of Typographic Style, a book that I consider canon.
So yes, hyphens, en dashes and em dashes are vitally important for typesetting well.
Van
Very Informative… Thanks!
Steve
Here, in the Punctuation 2 section, a different definition is given for the em-dash width, and if you look at Times New Roman and most other fonts you will find that the em-dash is much wider than the m or the M.
A point to note when designing em dashes is that they should be horizontal and run from edge to edge of the em square if you want to use them for continuous lines. Not all fonts have an em dash like this. It is up to you—the font designer—to decide how you want it to look when used with text. You could design the em-dash ——— for continuous lines and the en-dash for broken ones ––– Underlines are usually cotinuous _____ but hypens should normally be broken ----
Hmmmm. My definition for the width of the en and em dashes may be off. I’d seen a previous definition which based the dashes and spaces on the width of the characters ‘n’ and ‘m’. Bikkhu’s document seems to contradict this. This might be a matter of style and design, but it might be more technical too. I’ll have to do some research here.
I’ve just been checking fonts out here, and these dashes are all over the place! The more homogenized, Microsoft dominated a typeface is (at least in my opinion) the more likely it is to have the 2048 and 1024 funit em and en dashes. So looks like this is a pretty complex question. Franklin Gothic Book seems to almost exactly copy the width of the glyphs ‘n’ and ‘m’. I don’t really think it’s worth it. Take a choice: either make the en and em dashes the width of the n and m characters, make them 2048 and 1024 funits wide (assuming your settings: units per em is 2048) or go somewhere inbetween. You will at least be following a precedent of some sort because all of those are represented in my fonts folder.
This is actually one of Microsoft’s font quality, delivery and testing specifications pages and has some very useful information indeed. The direct link is to a Microsoft Typography page:
http://www.microsoft.com/typography/developers/fdsspec/default.htm