Missing The Point?

By The Metric Maven

Bulldog Edition

My days working as an offset pressman while attending college provided an education in confusion, and a certainty in my conviction that one should change the US over the metric system immediately. Most of the time we would use standard 50 lb offset paper (I’m not going to go into the meaning of this, that’s for another blog). Now and then we would print booklet covers on cover stock. It has been enough years that I don’t recall the details, but we had some card stock that was not the common thickness we normally used, and my father wanted to know its thickness for a printing job. I have explained the importance of thickness in offset printing in an earlier blog. Card stock thickness is described in points. I made an assumption that the thickness in points was linear with respect to inches, set up a proportion, and calculated the new thickness. My father apparently phoned the paper company. To my satisfaction, my computation was essentially the same as the value obtained. The odd part is that even though my father had worked for decades in the printing industry, and took great interest in its technical aspects, he (nor I) had any idea how thick is say 10 point card stock.

It turns out that a point is one-thousandth of an inch for card stock. Therefore 10 point card stock is 0.010″ thick. Of course there is already a feral unit for the point, called the mil, so one of them is unit proliferation and the other is nested unit proliferation.

Well, now the idea of 10 point type would make sense, it would be 0.010″ tall, right?  Well, clearly this can’t be right, the very letters at which you are looking are much taller than 250 µm. Well, it turns out that for type size, point means something else. In the United States when the point is used as a measurement of type size, it is equal to 1/72 of an inch. Therefore 12 point type is 1/6 of an inch high, and 6 point type is 1/12 inch high. So a point is either 0.001″ or 0.013888″ depending on the context?

Well, there is more measurement context to be found when using a point. Diamonds are measured by the point, which is equal to 2 milligrams, or one hundredth of a carat. That is of course the metric carat. If one follows the etymology of the word carat to its original meaning, it is a metric carob seed mass which is being described. Placing metric as a modifier in front of a non-metric, plant seed weight based unit, doesn’t make it metric. Just use metric units! Use grams! Don’t count out imaginary metric carob seeds! A metric ton is a Megagram not a metric version of a ton. We see that out in the everyday world of feral units a point can be both a length and a mass? When the meaning of a measurement unit depends on context, it’s not a measurement unit. It’s a metaphor.

Of course as computers were introduced in the 1980s it certainly would have produced an opportunity to re-think this entire point-based font measurement and switch it all to metric. As you are sure to already realize, this, of course, did not happen. According to Wikipedia:

In the late 1980s to the 1990s, the traditional point was supplanted by the desktop publishing point (also called the PostScript point), which was defined as 72 points to the inch (1 point = 172 inches = 25.472 mm = 0.3527 mm). In either system, there are 12 points to the pica. In metal type, the point size of the font described the size (height) of the metal body on which the typeface‘s characters were cast. In digital type, the body is now an imaginary design space, but is used as the basis from which the type is scaled (see em).

and

The desktop publishing point (DTP point) is defined as 1/72 of the Anglo-Saxon compromise inch of 1959 (25.4 mm) which makes it 0.0138 inch or 0.3527 mm. Twelve points make up a pica, and six picas make an inch.

This system was notably chosen by John Warnock and Charles Geschke when they created Adobe PostScript, by Apple as the screen resolution for the original Macintosh, and for the LaserWriter that launched the desktop publishing industry.[1][2] Therefore, the DTP point is sometimes called the PostScript point.

The use of hot metal type and letter press was anachronistic by the late 1960s and vanishing. Offset printing was supplanting it, and by the 1980s metal type was mostly found at garage sales, and used for decoration. The era of computer typesetting had dawned, and hot metal type was replaced with paper output. Did we keep picas and points because the vast majority of the population of the US was familiar with them? Of course not. Once again insider tradition trumped measurement innovation and reform in the US, and Adobe created it’s own pica. Again from Wikipedia:

  • The contemporary computer pica is 1/72 of the Anglo-Saxon compromise foot of 1959, i.e. 4.233mm or 0.166in. Notably, Adobe PostScript promoted the pica unit of measure that is the standard in contemporary printing, as in home computers and printers.

So no traditional barleycorns, or inches, but yet another measurement unit was foisted upon us without metric reform under the rubric that it’s “Traditional American.”

The Germans have a draft standard DIN 16507-2 for metric typography.  Here is a table:

It is my understanding this may not be the current draft version, but it is very useful in illustrating metric typographic sizes. One can see they are very orderly and in millimeters, a unit with which 95% of the world’s population is familiar. I’m very aware that quality typesetting and typeface development involves art, perception and numerous factors that are difficult to quantify. But why would one start with a completely unfamiliar measurement non-system of points?—rather than have a solid basis with metric dimensions?

Douglas Hofstadter spends a considerable amount of time discussing the notion that typographic fonts cannot be “meta-described” mathematically. (see Metamagical Themas, Chapter 13). Indeed I enjoyed calligraphy greatly when I was in High School and intuitively realize this. I generally used Olde English Script, I just don’t like Olde English measurement units. I recently read Just My Type by Simon Garfield which has convinced me that typography is a subjective art. But why would one start with a grid in picas and points rather than a familiar and accepted one like millimeters?  Whenever there is a chance for reform in US weights and measures it doesn’t happen and appears to not even be contemplated.

The point is not uniquely defined as a measurement unit, it can be mass, or multiple lengths. It could be a score in football or basketball, as well as other sports. Baseball at least uses runs. In mathematics a point is a zero dimension location with respect to a coordinate system. A point is a euphemism for dollars in stock market transactions. It can describe antlers of a deer or elk. It could also be points against your driving record.

I use TeX to create my engineering reports and documentation. The current situation with computer fonts and typography on computers is ghastly. With Tex I’m able to opt-into aesthetically satisfying  typesetting on my computer—which is compatible across platforms. I’m not remotely a TeXpert, but clearly the creation of ligatures, and kerning which reduces reading distraction, along with other important aesthetic features used in quality typesetting, would be best served if done with metric values, and not unfamiliar points and picas. These “modern” points and picas, were foisted upon us by the commissars at Adobe, to whom faux compatibility with anachronistic non-existent metal type demonstrated their ability for high tech “innovation.” I don’t see any point to what they did. You shouldn’t either.

Postscript:   Much like the weather, people talk about metrication, but Tony Planas, a mathematics instructor in Florida is doing something about it, by providing metric road signs.

6 thoughts on “Missing The Point?

  1. Your post reminds me of that one-hour Twilight Zone episode from the 1960s, with Burgess Meredith, twisted cigar in his mouth, operating a typesetting machine, and we watch his devilish articles appear letter by letter.

    Excellent post, Randy. It made me also think of the lack of standards-consistency even among those who use metric as their primary measurement system, e.g., the lack of use of the proper unit symbols, and the use of metric-based units such as the Angstrom (is that a “feral unit?”). Yes, mankind has yet to eschew all other nomenclatures for units except the one so neatly provided for all of us that comes out of that elegant-looking building in Sevres, France.

  2. Another reason they may have chosen to stick with points based on the inch is probably because they still use US paper sizes, which are sized in inches. That means that for 12pt font with a common line height of 1.5, or 18pt, gives 4 lines per inch. That allows for determining the number of lines per page by subtracting the top and bottom margins from the page length in inches and multiplying by 4. e.g.1/2″ top and bottom margins on 11″ long US letter paper leaves 10″ or 40 lines..

    It is, however, unfortunate that this means that the equivalent calculation on A4 paper is made even harder. I suspect this is why, when I went through school, I was never taught what exactly a point was. We were just taught that this is how font is sized in a word processor and we judge whether or not it’s big enough purely by sight.

    I looked into this issue a while back and played around with sizes in mm for fonts. A 4mm font size with line-height 1.5 isr 6 mm (4*1.5=6) per line. On A4 paper with a top margin of 20mm and a bottom margin of 25mm, that gives 297-45 = 252mm, or exactly 42 lines (252/6 = 42).

    In typography, it’s generally considered good practice to size fonts by ratios of a base font size lines are all evently spaced and headers with padding and margins take up an integral number of lines. So, by knowing how many lines fit per page and what your line height is, you can work around appropriate sizes and lengths for headings, margins, etc.

    So I wish common word processors supported proper mm based measurements, but the only thing i know of that supports it is CSS, and even then, printing a web page from a browser with sizes specified in metric doesn’t work so well. They internally do calculations in pixels, which is also somewhat based on the inch, and metric length units suffer from rounding errors during layout.

    • I worked around this problem by working out (with a ruler) how many millimeters a given point size for one font corresponded to, then I hard-coded this as a conversion factor in my program. Then I did it all over again with another font. For a third font, I got lazy and just used the height as measured by an on-screen ruler.

      In case you’re wondering, I’m making calendars.
      http://pdf52.uphero.com/calform6m_35.html

    • I think libreoffice has metric font support – as does gimp.

      Anyone that wants to push this forward might want to start a Wikipedia page called ‘software that supports metric fonts’.

  3. I ran across exactly this issue myself.

    Bottom line: there is no simple relationship between point size and the actual height of the letters on the page. Even if you figure out the relationship for one font, you have to figure it out all over again as soon as you change fonts.

  4. It is even worse then you mention. Checking Wikipedia, it seems different countries even do it their own way.

    http://en.wikipedia.org/wiki/Point_%28typography%29
    http://en.wikipedia.org/wiki/Typographic_unit

    In 1886, the Fifteenth Meeting of the Type Founders Association of the United States approved the so-called Johnson pica be adopted as the official standard. This makes the traditional American printer’s foot measure 11.952 inches (303.6 mm), or 303.5808 mm exactly, giving a point size of approximately 1⁄72.27 of an inch, or 0.3515 mm.

    Has anyone ever seen a fraction where there is a decimal number in the denominator?

    http://www.cl.cam.ac.uk/~mgk25/metric-typo/

    Japanese typesetters use the unit Q (quarter) for font sizes, where 1 Q = 0.25 mm, i.e. the same modulus recommended by DIN 16507-2.

    This measure coincides nicely with the most common pixel size on computer monitors. For example a typical CRT screen has a display area of 320×240 mm, divided into 1280×1024 pixels, which makes each pixel 0.25 mm large.

    Now, if all of the printers come from Asia somewhere, what system are they using?

Comments are closed.