What is an ‘en rule’ – and why does it matter?

In pre-computer days, when artwork was created and drawn on a drawing board and pasted-up on line-board, the processes were fairly complicated and required a thorough knowledge of the production and print processes. The advent of the computer into design and artwork was a massive step, and I benefited from that because I used to create artwork the old way and was now able to be much more adventurous (and quicker) by using 'desk-top publishing' as it used to be called.

Things have come on a long way since then, but not always for the better. Modern computer software has meant that anyone reasonably computer literate can buy software and produce a result. Because they have personally produced it, they naturally think that it’s wonderful. They can 'work' the software, and output something which, at first glance, appears quite good.

In actual fact, upon inspection, these results do not always stand up to scrutiny. Are they really the sort of thing a professional company should be putting out? Do they present the image of the company correctly? Is the photography (if applicable) clear, enhancing that message and adding to the general effectiveness of the leaflet, advertisement, web page – whatever is being created. And is the type legible and the layout coherent, so that the reader can follow the message?

And that is where you can tell the difference between a professional and a mediocre job. Quite often – in the typography.

Have a look at that last paragraph. Just before the last three words there is a dash. Or a hyphen. Or – what? There’s another one!

It’s an en rule. Typographically, (to quote the Oxford Guide to Style, which is my preferred bedtime reading) it is 'as the name indicates, a rule that is an en in length, which makes it longer than a hyphen and half the length of an em rule'. We used to use the term '1 em of set' in the days when type was a physical chunk of lead. So, if you had 12pt type, 1 em was 12pt wide. Similarly, on 72pt type, 1 em would be 72pt wide. And therefore, an 'en' on 12pt type would be 6pt wide.

And that’s what you should use, not a hyphen, which is altogether shorter. This - is a hyphen, whereas this – is an en rule. And this—is an em rule (sometimes called a dash), which can be used instead of an en rule, but notice how with an em rule, common usage dictates that there is no space either side of the rule, whereas an en rule has one space either side. And a hyphen? Well that should never be used in this context, so it doesn’t really matter whether you have space either side or not. It’s still wrong.*

Does all of this matter? Probably not, unless you care about the subtleties of language and the appearance of good typography. In a few years, everything will be reduced to the good old hyphen and we’ll be non the wiser. Now the en rule is on the decline, I read that people are questioning the necessity of the apostrophe. Where will it end?

Still, the en rule has one use for me. Whenever a leaflet, magazine, poster, brochure or even web site is presented to me I quickly scan it for the presence of en rules. If there are none – only hyphens – then I know. This material has been created by someone who doesn’t quite understand what they're doing.

To get an en rule on a Mac, hold down the alt key and hit the hyphen key (to the right of zero at the top of the keyboard). If you hold down the shift key and hit the same key, you will get an underscore. If, however, you want an em rule (remember, the longer of the two), hold down the alt and shift keys together and hit the hyphen . This is on a Mac. I’m not sure what the codes are on a PC. Or on an iPhone, so worryingly, all of my text messages have to use hyphens instead of en rules. The recipients must think I’m an idiot!

*The appearance of en, em (and any other rules) varies with different fonts. The particular font I am using here does not show very marked differences between  the en rule and the hyphen, although there is one shown when they are juxtapositioned as here where an en rule follows a hyphen '- –'. I would also add that the guidelines for which to use and when, and whether to have spaces, are many and varied. I will not try and include them all here but would recommend using a good style guide. It may seem rather fussy looking at all of the uses when the eye reads the type so quickly and does not take in the detail, but if you have a section of text which is complicated with quotations and other parenthetical matter, correct use of rules can make for greater clarity.

And one last example. I'm sorry, I can't resist this one. This is a direct quote from the above mentioned Oxford Guide to Style. "Use the en rule spaced to indicate individual missing letters: 'F – – –  off' he screamed". Sorry about that! If you must swear, at least do it in style.