I Love Typography

Reviving Caslon

Part 2: Readability, Affability, Authority
[read part one]
When their words are put into print, writers want the text to be inviting and welcoming, so that readers will read what they have written. And they also want the text to have an aura of credibility, so it will be taken seriously and maybe even accepted.

When I read Einstein’s Autobiography many years ago, as both a writer and a lover of type I noticed and remembered that the font it was printed in seemed extraordinarily approachable and easy to read—even while projecting strength and authority. James Mosley reports that printers used to say, “You can’t tell a lie in Caslon.” And then he adds wryly: or is it that you won’t get caught? When I started my revival of Caslon, I set out to revive these qualities I had seen in its letter press Linotype Caslon Old Face: readability, affability, and authority.


What does it mean for a text to be “readable”? In English some have made a distinction between legibility and readability:

“Legibility” is based on the ease with which one letter can be told from the other. “Readability” is the ease with which the eye can absorb the message and move along the line.”
Types of Typefaces (1967) p. 84-5.

The same distinction is discussed by Walter Tracy:

[Readability] describes the quality of visual comfort—an important requirement in the comprehension of long stretches of text, but, paradoxically, not so important in such things as telephone directories or air-line timetables, where the reader … is searching for a single item of information [and where legibility is most important].
Letters of Credit (1986), p. 31.

My main goal in my revival was maximizing this quality of “visual comfort.”

What qualities of a typeface make for visual comfort? Here there is no consensus but raging debate, including even over whether the concept is valid. I will not go into the debate here, but just relate my own ideas on reading comfort that I have in effect tested in creating my revival. (For the debate see the survey paper by reading psychologist Kevin Larson, and this Typophile thread.


We can see in the following graphic that legibility of individual letters is indeed different from the readability of whole words:

All of the letters in “legible letters,” above can make easily readable words when they are used to form words with their mates in the same style and weight. However, when letters with different weights and styles are mixed, the words can only be read slowly, with difficulty. What this shows is that the design of individual letters is not enough to make for readability. Some kind of harmony among the letters is needed for our brain to be able to capture and process either individual letter parts, or whole letters, or both, so that we can quickly identify words.

This illustration suggests that the brain is putting some kind of grid or matrix over the word, and that it identifies letters and words by how the black and white fall within that matrix. This idea also accounts for two of the qualities that are prized in text type: regular rhythm and even color.

Here, readability noticeably deteriorates with irregular spacing. Readability also suffers when rhythm is disrupted by irregular widths of characters:

Indeed, with a “Fourier transform,” which mathematically shows the regularity of variations of black, text fonts show a fairly, but not completely regular pattern:

Here the white bands show the frequency of the black running across the page, with the distance between the whites I believe being about the width of the n. (Thanks to Peter Enneson for the graphic.)

Both the evident regularity and the deviations from total regularity are, I think, characteristic of good type. The regularity enables the brain to lay the grid over the type, and the deviations from total regularity are what we “read” as the message. Uneven color (density of black) also harms readability:

A plausible explanation of the need for even color is that too much variation in light or dark constitutes “noise” that interferes with the “signal” to the brain from the different parts of the word.

In addition to even color and rhythm, there are two more factors that seem to be critical to ease and comfort in reading. One of these is the overall blackness of the type. In fact, bold type is almost never used in extended text; it seems fatiguing to the eye. And if the type is too light, the contrast with the paper is too little, and the text is hard to read.

The roughly ideal stem width was already traditionally specified by scribes, with the x-height being between four and a half and five widths of the nib of the pen.

Nib widths — source.

The great type designer Adrian Frutiger has written:

It is a quite specific ratio of black to which gives the x-height band of a typeset line a grey value which the reader finds to be “normal”. These proportions are perceived with astonishing sensitivity … An average value … is a theoretical band of 5 stroke thicknesses. The grey value is composed of 2/7 surface coverage and 5/7 white space, corresponding to a density of rather less than 30 per cent.

In testing James Montalbano’s Clearview Highway typeface for road signs, researchers found that with the stroke ratio near the traditional 1:5, viewers could read the signs sooner and farther away than with bolder weights. While signs and extended text are not the same, the corroboration of this ratio is striking. The advantage of the total white being roughly twice the black, as Frutiger pointed out, may relate to the eye needing a clear figure-ground distinction. It may also relate to the advantage of having the counters (white space within letters) big enough—a factor that showed up in other tests of Clearview Highway.

A final factor in readability relates to a special problem of latin type, which is its vulnerability to the “picket fence” or “zebra” effect, which causes that type to “dazzle.” If you look at a line of black pickets against white, they dazzle:

Similarly, because of the need for regular rhythm, this dazzle is always threatening to happen to roman type, the most common complaint being about the “dazzle” of Bodoni:

So a typeface designed for reading comfort will also try to avoid this ‘picket fence’ and the associated dazzle.


Given the constraints of even rhythm and color, and a narrow range for the weight of stems and the ratio of black to white, how different can one good text font be from another? Erik Spiekermann has said that there can only be a 5% difference, and that may be true.

Because I had found the letterpress 12 pt Linotype Caslon Old Face particularly comfortable and inviting, I took as my working hypothesis that there is some ideal in proportions, the weighting and modulation of strokes, and spacing, and that Caslon’s Pica 2—and the Lino revival of it—had somehow hit nearer the mark in some ways than other faces. Further, my feeling was that even though it might not make a huge difference to reading speed and comprehension, hitting the ideal would communicate itself visually to the reader as a feeling of ease and welcome—and then would of course be in fact an effortless read.

So I set out by trial and error, with variations, to see what would work. And I triangulated between scans of the original and close copies—letterpress Lino Caslon and Founders Caslon—on one hand—and Adobe Caslon on the other. Adobe Caslon is a very well drawn face by a superb designer, Carol Twombly, but for me didn’t have the magic of the metal versions. Why? What was missing?

When we compare Adobe Caslon, the original, and Baskerville, we can see that it is kind of a “Caskerville”, looking like it’s morphing from Caslon to Baskerville.

As I have said, deciding what is “essential” in Caslon is somewhat of a Rorschach test. I tested a lot of variations, and two things I noticed first: Adobe Caslon “n” is wider, and the top arch is thinner and differently shaped than the original.

Both of these turn out to be important to the “dark but open” look that I think is attractive in Caslon.

The width of a typeface is one of the basic features of the “DNA” that give it its look, its texture on the page. Other basic features affecting rhythm are the spacing between letters, and the thickness of the stems. Together, these give a characteristic rhythm to the text. I gave my characters about the same stem width as letterpress printed Lino Caslon Old Face, and Adobe Caslon, as this suits modern printing. However, I made them slightly narrower than Adobe Caslon, matching the original Caslon Pica 2, and spaced them a little looser—a little more “air” between letters. The result it that they take about the same space, but Williams Caslon text (above) has more of an open feel than Adobe Caslon (below) at equal x-heights:

In order to get the effect of print at small sizes in looking at these on screen, move slowly back 6 feet or so away from the screen. That’s the only way to emulate print, because if you make text small on the screen, you get artefacts from low resolution (96 dpi screen vs 2500 dpi print), and it doesn’t look like 8-12 point print. And if you make text large on the screen, and look at normal screen distance, you don’t get the optical effects that happen at small sizes. The critical variable according to psychologists is the visual angle spanned. With larger type on the screen, walk slowly backing away from the screen, and you get a pretty good emulation of print. Try it, you’ll see!

Two special visual effects operate at text sizes. The first, and most well known, is that the spaces between letters appear tighter. In order to have a readable rhythm, the text sizes need more letter space than at larger, display sizes. In my view, many types today, including Adobe Caslon, and especially Times New Roman, are a little too tight. Just a little more “air” between the letters makes for a more comfortable read, to my eyes; so I have given Williams Caslon Text a hair looser spacing than most types today. The spacing is not a separate matter from design, though, as the width and design of the characters need to be “tuned” to the spacing to get the overall effect.

A second effect is that as the characters shrink in size, the “thins” get thinner visually faster than the “thicks” get thinner. This is why traditionally at very small sizes, 8 points and below, contrast between thick and thin is reduced for the sake of readability. And in letter press printing, an additional reduction in contrast was caused automatically by ink spread, as I explained in Part 1 of this essay. That is why the initial practice of basing digital versions of old typefaces on the 14 pt outlines, as I have heard, resulted in anaemic looking and less readable text type.

The adjustment for text size is, however, not simply a matter of increasing the thins by a fixed amount. It turns out that the eye responds differently to changes in horizontals, verticals, diagonals, and joins. So thickening is a matter of sensitive modelling of the arches so that the whole character appears ‘dark’, but does not become ‘clunky’ at the intended size—a fault of some contemporary “dutch” style types, to my eyes.

So here is a comparison of the modelling I did on Williams Caslon Text with the original, Lino Caslon Old Face, and Adobe Caslon:

The Williams Caslon Text regularizes the original, rejecting the leftward lean of the stem, and smoothing the arch. But it follows the way the weight is modulated through the shoulder. At the same time, the stems are as light as Adobe Caslon, and even lighter in the baseline-to-x-height region, as they have a “waist” in that region, following the original. Williams Caslon Text in red, Adobe Caslon in black.

The result is, as we can see in the previous graphic (viewed from a distance), and more so in extended printed text, that Williams Caslon Text looks both darker and more open at the same time.

The “waisting” also helps break the picket fence, so that the letters do not assault with dazzle, but rest invitingly on the page. Here are Williams Caslon (above) and Adobe Caslon (below) with a challenging word (move away from the screen again!):

And Adobe Caslon is already better than many fonts in avoiding the “picket fence”, because of its old style serifs.

There are other features designed for both even color and to have a “dance” of varying shapes across the page, particularly at x-height. Here is the result, as seen in Boston Magazine:

II. Affability and Authority

The same features that promote readability contribute to the affability of Caslon: its welcoming and unpretentious look. The most important part of that is probably just the ease with which it can be read. In addition, Caslon has a hand-molded look which has a human touch that conveys more warmth than sharp geometry. Caslon’s sturdy serifs also give a message of reassuring solidity. The rounding of the serifs that comes from ink spread is also a softer, more relaxed and comfortable feeling than faces with sharp serifs. However, filled-in joins simply look clotted and ugly, so here I have not followed the ink-spread look. Clotted joins would look antiquarian or nostalgic, while the sharp joins look clean and contemporary.

The “dark but open” look affects not only words, but the text block. Because of the open look, Williams Caslon Text can be set with relatively less leading, and still be readable. Many contemporary darker types, such as Quadraat, call for more space between the lines to invite the eye, resulting in more of a “black and white stripes” look. In contrast, and going against current trends, Williams Caslon can be set tighter vertically, resulting in more of an even “lattice work” look, which somehow makes the whole page look more open. In order to enhance this, I have also provided as an alternative “stylistic set,” accessible through Open Type, a version with shorter descenders, matching the short descenders of Lino Calson Old Face. This enables the type to be set with about 1/2 point less leading.

The feeling of authority of the metal Caslons comes, I believe, primarily from its assertive caps. Caps are an essentially different alphabet, encompassing more white space than their lower case companions. Since they serve as “markers” of a sentence beginning, or a proper name, the difference in look offers an opportunity that can be taken advantage of, rather than minimized. While caps that more match the color of the lower case are a valid choice, the traditional more dominant caps can work aesthetically, and in this case add considerable strength to the look of the face.

In Adobe Caslon, the caps were made assertive by making them tall—taller than they are in the original, while they are lighter, and more tapered inward. My approach was rather to keep them the original height and make them straight sided—which I think looks stronger—and the serifs more beefy, as with the lower case. Williams Caslon Text thus has waisted stems on the lower case and straight ones on the upper, whereas Adobe Caslon is the other way around.

Finally I should say that a key to both the aesthetics and the readability of the font has been looking at the letters printed out at size. Caslon has always been a “workhorse” rather than a “showhorse.” Its sturdy serifs were a choice to put readability and reassuring strength over the elegance of a Garamond. On the screen, large, Williams Caslon Text looks too clunky, whereas printed at text size, to my eyes it hits the right weight and contrast for comfortable reading, and is aesthetically appealing.


The original italics of Caslon Pica 2 are to my eyes just not that good, and would probably have never been revived except for the qualities of the roman.

And in fact, in the 19th century, this seems to have been completely recut, and the 20th century revivals based on the recuttings. To my eyes the biggest problem is that it is too narrow for decent readability. Even though companion italics don’t have to be so readable as the roman, the original starts to be a barrier to anything more than a few words. Evidently, Carol Twombly felt the same way, as she widened the italic considerably. As I wanted it to be able to set several lines, e.g. of poetry as well, I also widened it, and made it a bit more upright as well.

Making it more upright turned out to be more complicated than I thought, because I wanted to preserve the variation in angle of the stems, which is an old style feature that was abandoned in the 19th century recuttings, and also in Adobe Caslon. But I did discover a systematic visual logic in the variations, and I reproduced that in a more upright version.

Caslon Italic Comparison
Caslon Italic Poetry Sample

Finally, there was the question of swashes. The original Caslon had only swash caps for JQTY. Various additional ones were added in the 19th century. Now, the tendency is to add swashes for all the alphabet, though some work better than others. Swash caps are an interesting hybrid, because they are a cross between slanted rigid roman caps, and script. That tension or contradiction between rigidity and exuberance gives them a happy, show-off quality.


Williams Caslon Text is one of the first of the new “Premium Open Type” fonts from Font Bureau, with small caps, both roman and italic, Central European characters, and many other different features, such as six different styles of numbers. And everything is kerned to its mates. For example, swash caps are kerned to italic small caps, an attractive and unusual combination. While most of the thought went into how the lower case roman should look, most of the work went into the 3,000 characters and 16,000 kerning pairs. In addition to readability, affability and authority, the font needed a comprehensive character set, and functionality to match, to work effortlessly and enjoyably for designers and readers.

William Berkson is a writer and type designer. Information about his new book, to be published in October, is here, and his new revival of Caslon can be found here.


  1. Bert Vanderveen

    Love this! Text book material. I want more…

  2. This second part have enjoyed my day, thanks a lot.
    It’s really interesting to see how deep and precise were your researches… what a huge work… (and beautiful italic ! )

  3. Birdie

    I missed the first part of this blog series, but this second part made my day. Thank you for such an in-depth explanation. Your Caslon is quite beautiful - the italic had me sighing happily! Well done, you!

  4. Matt

    I like this post a lot. The move away from the screen thing on the word ‘minimum’ blew my mind. It was very difficult to read when I just sitting in my regular position and came into crystal clear focus as i backed away.

  5. William,

    I really enjoyed this article. Great stuff.

    Best of luck with the sales.

  6. As a “love to read about typography, but not a typographer” type of person, this was super interesting to read. I find it neat that there are crafts like typography where someone can spend enormous amounts of effort on something that 99.9% of the world will only see in passing, or never notice. Great read.

  7. Lok

    Really like what you did with the font, and vey nice to read about the process.

    I’m also taken by the font you used to write this article (serif and sans-serif work very nice together). Would love to know what they are..

    best of luck with Caslon..

  8. Absolutely loving these articles!! :-)

  9. Two super-interesting and entertaining articles on my favorite subject, plus a great new face! Thank you!

  10. jstypo

    What an interesting article and what beautiful work, you must be very pleased indeed. Congratulations!

  11. Lidsay Rollo

    I have used the following definitions to distinguish between legibility and readability:

    Legibility: that combination of type and display that best aids the ease and speed with which the reader can recognise the structure and content of the text;


    Readability: the choice and order of words and typographic cues that best allows the reader to comprehend the text.

    The legibility options are more important in technical and professional books and journals, where several levels of typographic cueing may be necessary to delineate the structural complexity of the subject matter.

    These criteria apply regardless of the type face used, not just to Caslon

    Newspapers, general magazines and fiction rarely need more that four typographic cues: title or chapter heads; subheads or section heads; paragraphs, and direct speech signals.

  12. Lidsay Rollo

    As a sepaqrate observation, the line length of this blog section is twice the recommended lneth for comfotable reading.

    Robert Bringhurst and established printing practise suggests limiting the line length to 65–75 characters, including spaces.

  13. I agree with the observation by Lindsay Rollo about line lengths in the comment section. I hate long lines.

    The strobing effect is very serious; I find it worsens symptoms of migraine. I would not be surprised if it can actually set off an attack in some, the way repetitious patterns are wont to do. Varying slant and axis helps, I think.

  14. Thanks all, for your appreciative comments.

    Lidsay, I would slice the meanings of “readability” a little differently. There is an important sense of “readability” that has to do with the quality of the writing, and not typography. As a writer, I have always struggled to make my writing as readable as possible, quite aside from what typographic form it ends up in.

    So I would give “readability” two meanings: one that applies to rhetoric, to good writing, and another that applies to typography. And I would include both layout, including titles, and typeface in the second, typographic meaning. One the first meaning, good writing, my guide has been been the wonderful book “Style: Lessons in Clarity and Grace” http://www.amazon.com/Style-Lessons-Clarity-Grace-10th/dp/0205747469/ref=sr_1_4?ie=UTF8&qid=1288806224&sr=8-4

  15. Bill,
    Great article! Glad your “baby” was finally born and now has a worthy birth announcement!


  16. After reading Part 1, I was really looking forward to Part 2. It was even better than I could have hoped for. Congratulations, William!

    This case study could easily be the basis of a entire course on Design of Typefaces For Readability. You should make a movie.

    You refer in the text to the “artifacts” of lower-resolution. (I prefer “arti” to “arte”, but that’s personal preference).

    I think there’s a real opportunity for you here to work with a hinting expert to create something quite special…

    For valid technical reasons, it will be almost certainly be many years before screen resolutions (other than the very small screens of mobile phones) increase to the point at which their constraints can be ignored. Yet people are spending more and more of their time reading from screens.

    The constraints of ~96 pixels per inch (ppi) might be too harsh. However, it would be worth experimenting to see how hinting could be used to improve screen readability at ~133ppi - the resolution of the iPad and many current laptop screens (like the MacBook Pro on which I’m typing this).

    I think you and the right hinter might be able to turn Williams Caslon into an exceptionally good reading face for eBooks and eMagazines at that higher resolution.

    (One editor’s nit-pick: “effect”, not affect…)

  17. Lidsay Rollo

    William Berkson

    I take your point about ‘readability’.

    Would this variation of the definition be acceptable ?

    Readability: the choice and order of words the best engages the reader’s interest combined with typographic cues that best allows the reader to comprehend the text.

  18. I’d never heard of Caslon before this article! Nice job.

  19. I enjoy type, but the current obsession with typography amongst amateur designers and web designers doesn’t get much beyond a typeface craze (it was Helvetica a year or two ago…), a little kerning, and a bunch of beginners happily repudiating Comic Sans.

    Reading articles like this really inspires me to learn more about “real” typography, all the details and nuances that go into it. Thanks for the wonderful read!

  20. johno

    Bill Hill
    That was my edit from artefacts to artifacts. As a Brit living in Japan, I tend to mix my spelling. I think artefact is the American-English spelling…?

  21. I’m a Scot, living in Hawaii. Wikipedia suggests the opposite, that “arte” tends to be British, but that it’s more a “preference” than anything (unlike defence/defense).

  22. Fantastic write-up. Never learned so much about typography than I have from this article. Fantastic font work too.

  23. On affect/effect. I have always found it very confusing which to use, but I think I got it right here. I have followed the friendly and humorous grammar book “Woe is I”. It says, “If you’re referring to a thing (a noun) ninety-nine times out of a hundred you mean *effect*. … If you mean an action (a verb) the odds are just as good if you go for *affect*.”

    There are exceptions, such as “to effect change”, and “the patient has flat affect” (expression of emotion).

  24. Thanks for the great article! I love the picket fence analogy.

  25. hi as a person who needs reading glasses-who has 5 pairs which always congregate somewhere else but not to hand-I find that fonts are important as it helps me read unaided-however numbers are impossible….the 6 can look like an 8…3 also like an 8 if printed on poor paper…I need numbers where the 3 has a tail where the 6 has an upward tail and the 9 a downward tail…..I suppose bad numeral fonts make me find the specs
    Nice read MiKe

  26. I love this article, it summed up how my last two days were in picking a perfect serif font for my website from typekit.

    The two fonts I kept going back to were FF Meta Serif web pro and FF Tisa. They were both similar with very subtle qualities, one felt warm and enviting (almost fun) the other felt a bit sharp. After examining the details I began to understand why. It was those minute subtle differences that made them work at different sizes. At the end I realized that I will be using them both

    After I had to verbalize my reasoning to my wife, it became less about my instincts (aesthetics) and more about the logic (or since behind the fonts). This article confirmed what I was thinking but in more detail.

    Thank you for another great article.

  27. I like the swash caps, good article interesting read.

  28. Nina

    Great site. I was just looking for fonts last week and Caslon was one of the ones I selected.

  29. Great advice and opinion on our good and legible and readable buddy ‘Mr. Caslon’. I liked your reasoned analysis as well. Learned much tonight. Thank you.

  30. L Dunn

    Fascinating - particularly all this talk about ‘authenticity’.

    Particularly in part 1 of this article, it seems that type (re)design is really much more of a performance than you might imagine. I’m reminded of the problems outlined in Jonathan Miller’s ‘Subsequent Performances’ (Faber, 1986), and latterly Richard Taruskin’s critiques of ‘historically informed performance’ of Early Music in ‘Text and Act’ (OUP, 1996).

    What is particularly fascinating too is the fact that a typeface, like a play or a musical work, has an ‘afterlife’ - it is constantly subject to reinterpretation, modification, reappraisal. All of these things relate to their contemporary context - so that Caslon altered in the C19th has a nineteenth century ‘look’ from our perspective, despite there apparently being no deliberate attempt to locate the typeface temporally. Founders Caslon ‘looks’ 1990s through the unintentional intrusion of context, despite its rigorous derivation.

    In this sense typography is much more of an allographic, or performative, artistic discipline. An originating model (or text) is established, and ‘realised’; though each realisation (and its changing contexts) alters the way the model is perceived.

  31. I have looked at many a printed character highly magnified, and what I have observed is that to do a “rigorous” derivative you would need more control of gray levels, or a renderer that can accurately simulate ink spread. For instance, serifs often are (in my observations) a lighter gray than elsewhere in the character, and the ink tends to collect not only in the brackets but at the ends. If the paper isn’t very hard, coated paper then there also is a very ragged outline that is lost in a digital reproduction.

    Part of the revival problem, then, is to choose outlines that have a sharp divide between sides and give similar impressions to the eye of the shapes one is seeing, as do the original characters represented as ragged shades of gray.

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