Getting the Point

We all need printed material of some kind, and in the process of getting it we are introduced to some oddities of the language in which printers confer. It's a language that goes back centuries. Our introduction comes from using word processing programs, more so with page layout programs.

When printers were obliged to change from Imperial measurements to metric, they changed easily. Just convert from ancient measurements to and from centimetres and millimetres as they had previously converted to and from inches. The end user was still left puzzled with talk of points, picas and ems.

One of the problems is that when you look at type that is supposedly the same size, it can look very different, as in the examples in Figure 1 below. The reason for that, is that the point size is based on the height of the metal slug on which a type character was made. That was in the days when Movable Type was a description of how things were printed, not the name of a popular blog software.

What you can be certain about is that a specific number of lines of the same size type placed beneath each other will occupy the same depth on the page. Six lines of 12 point type make an inch, or 2.54 centimetres. Or at least they do now. It was not always so.

A4 Easier Than Paper Elephants

Now having got the truth about type sizes clear in your mind, we can turn to the paper the type will be printed on. Fortunately, in this, we have become thoroughly up to date with a very simple mMetric system. The paper you normally use will be A4, and that, cut in half across it's width, creates two sheets of A5. Every sheet is in the same proportions, based on the square root of 2, so a layout created for A4 can be printed on A5 by reducing it overall to 71 per cent of the original. Getting from A3 to A4 similarly means a 71 per cent reduction.

Of course, it is not always so easy, and there are other ranges, of sizes as well as the "A" range, known as B and C. They are somewhat larger, intended for uses where a job has to be trimmed after printing, or changed into something else (known as "converting") such as in making envelopes.

Standard sizes of paper also make it easy to compare weights of paper, and everything is compared in "grams per square metre" so you can easily see that A4 paper at 70gsm is lighter paper than A3 paper at 80gsm.

OK, were you feeling sorry for having to have awkward conversions from points to millimetres? Feel sad no more. In paper, the USA has a very different system. The weight is defined as the weight of 500 sheets of the paper in the size it was cut from.

Most letter size paper (slightly wider and shorter than A4) is sold as 20 lb but a heavier paper might be made. in a different size sheet originally, so a very thin card of exactly the same grams-per-square-meter weight might be described as being 28 lb.

That abbreviation "b" for pound may need explaining, also useful to those of you who have grandkids with Tamagotchi electronic toys. It's those Americans still using the abbreviation for the Latin word libra to mean pounds.

Other paper sizes in the US are known by names such as legal, ledger, post, crown, demy and, strangely for a republic, crown and royal. You may occasionally find an elephant (28 x 23 inches) and a sheet known as a double elephant was originally used for wallpaper before they started making much longer rolls.

Black and White

This brings us to another core measurement for type — the Pica, pronounced "piker" just like the Australian term for someone who wants to opt out of the crowd. Collingwood supporters may like to know that the word derives from the Latin for magpie, perhaps indicating the colours in which most books were (and are) printed.

There are 12 points to a Pica and the Pica, conveniently for Americans is now exactly 6 to the inch, which makes it devilishly difficult to accurately convert to millimetres.

The Brits and the Yanks used to have 72.27 points to the inch, and the change to 72 was not the decision of some international committee. Chuck Geschke and John Warnock were working at Xerox Parc (that's Parc for Palo Alto Research Center, not as in lawns and shrubs) when even the powerful computers of that time would have had trouble doing large numbers of calculations to two decimal places, so they created the Postscript printer description language with just 72 points to an inch.

I've seen that story referred to as apocryphal, so 1 asked and Mr Warnock told me the story was in fact true — adding that "because fonts had to be recreated for PostScript, we believed that no great harm would be done by making the assumption".

Those two people, who founded the Adobe software company really did change the world of printing. But we are getting ahead of ourselves...

Type sizes were defined in a somewhat different way from the 15th Century in Europe, when sizes progressed through brilliant, diamond, pearl, nonpareille, colonel (or mignon), petit, borgis, corpus, cicero, mittel, tertia and up as far as small canon, and canon, the latter being about 36pt type in our present measurements.

Instead of asking for that address to be a point larger, you could have asked, in French of course, for the colonel to be petit. In other words from
about this (7pt) to this (8pt). And the headline could be changed from a small canon (33pt) to a large canon (43pt). Those terms lasted quite a while though by the 1940s a reference book said canon were outdated and should be measured in ciceros.

The King's Foot

Ambroise Didot, a Frenchman, created some real standards in 1784, when he related the point to the French foot, the royal foot, specifically the King's foot. So one foot was divided into 12 pouces, one pouce into 12 lignes, the ligne was divided into 12 points. One point was 1/1728 of the King's foot. Then just five years later along came the French Revolution and just as English speaking printers were to do when metric measurements entered their world, the French printers decided that they'd go on with points and that there would be 2660 points to one meter. (Have I just rewritten history? No, just simplified it a little.)

You will also hear a pica referred to as an em because an em is 12 points, but, just to get you really confused, it does not have to be. If you hear a width mentioned in multiple "ems", such as that a column in PC Update is 14 ems wide it will mean that it is 14 picas wide. However, an em is named after the letter M which, in most typefaces is a square character, so a the letter M in a 12pt type will usually be 12 points wide, the same as a pica.

If the first line of each paragraph was to be indented, it would probably be indented by a square of the height of the type, and that would be called an em — if it was 10 point type the indent was 10 points.

By now you may be thinking that it is all designed to confuse you. Let me assure you that this is so. (Should I have had "not" in there somewhere? I wonder...).

About the Author
Gordon Woolf is a long-time Melb PC member who once rebuilt a British Vertical printing press and has been narrowly missed by a spurt of molten type from a typesetting machine, but who prefers computers even though they are no more predictable.

Reprinted from the July 2006 issue of PC Update, the magazine of Melbourne PC User Group, Australia

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