Serifs and Typography

Any mind-machine interface has 3 attributes: Learnability, Efficiency, and Memorability. An optimal system can be learned easily, used quickly, and is easy to remember or re-learn. Writing is a mind-machine interface. This paper focuses on efficiency. There are two warring factions of fonts, Serif and Sans serif. To determine the most readable of the two requires understanding of the reading process.



Eye movement happens in saccades and fixations. Saccades are rapid eye movements, each saccade starts with maximum acceleration, reaches maximum velocity if the distance is large enough, and ends with maximum deceleration. These movements are too quick for us to be aware of them. Between these saccades are fixations. During a fixation the eyes focus on one spot. Visual detail is greatest at this point because it is at the center of the depth of field and the density of light sensitive cells is greatest in this region of the retina.

As a line of text is read, each fixation gathers detail from a portion of the text, high detail at the point of fixation as well as lower detail from the surrounding area. Longer fixations get more data, but there is a limit to what can be deciphered without another saccade. So a saccade moves forward to get more detail. A skilled reader moves far enough forward to get new information, but not so far as to miss critical detail. Saccades usually move forward, a backward motion is a regression. Regressions usually occur when a forward moving saccade goes too far. When the end of the line is reached a return sweep places the eye at or near the position of the next line of text. Sometimes the position after a return sweep is not quite right and requires a regression to correct (Tinker).

With readable text and a skilled reader, fixations are brief, saccades cover several phrases, regressions are relatively infrequent and usually are after a return sweep. A less skilled reader will make more fixations (and therefore smaller saccades) and will make many regressions. Yet, even a skilled reader will have longer, more frequent fixations with a higher percentage of regressions when reading difficult text (Tinker). The difficulty can come from difficult writing such as abstruse vocabulary, awkward sentence structure, or poor word choice. The difficulty can also come from bad typography such as excessive italics, small characters, ALL CAPS or insufficient contrast.

This informs us as to the optimal font. This optimal font should have unique word forms: saccades of skilled readers move many characters at a time across multiple word boundaries, so words are recognized as a whole instead of combination of separate characters. Word shapes should be unique when blurred, this allows longer saccades. And the font must look similar to what the reader expects, since this allows fast recognition.

Some sources claim that serifed fonts are superior to sans serif fonts for purposes of body text because they can be read faster and more accurately. Serifed fonts have dominated print. Of the books on my shelf (actually now scattered around the room), 3 are sans (these are by artists), and 45 are serif. Only 6% of my books use sans as body text. Are serif fonts more readable? Possibly. Perhaps the serifs promote healthy reading habits by guiding the eye along the line of text. Considering the saccadic movements of the eye, this is unlikely. Serifs make individual letters more distinct. For example, though I and l are easily confused, there are slight details in their serifs. The differences are smaller or nonexistent for sans fonts. This also has little impact on readability, since words are read as wholes, rather than sequences of characters.

If serifs dominate print, sans dominates the web. Are sans fonts more readable? Possibly. Roman masons carved letters into stone, and the chisel stroke to end a line left a perpendicular mark at the end. During the Renaissance and the introduction of the printing press, these letters were used as models. Since serifs are a historical byproduct, the result of limitations that no longer affect us, is it better to leave them behind?

There are a few possible reasons for this. “A Web page is not a paper page” writes Joe Gillespie, a graphic designer specializing in new media. “It needs to be treated differently - as differently as you would approach calligraphy and stone carving.”
Good print fonts are not necessarily good screen fonts because there is a fixed grid of pixels and the lighting is fundamentally different. Designing a good screen font is like designing in bathroom tile. There is a limit to resolution, and there are finite fixed positions. A possible circumvention of this is anti-aliasing, that uses values of gray where the edge of the character does not match the edge of the pixel. This gives the appearance of a smooth edge, but reduces contrast. In a study of print fonts on the screen, anti-aliasing performs poorly compared to rasterized (not anti-aliased) fonts (Bernard and Mills). Small details in print fonts, such as serifs, are difficult to convert to the grid without careful attention, since automatic methods may reduce them to visual noise that slows down reading, and so with fonts designed for print sans may be more readable.

Print media works as a light subtractive media, where light falls to the page, and the contrast comes from the difference in absorption of light. The computer screen is an additive media. The screen emits light, and if too much external light hits the screen, contrast is reduced, exactly the opposite from print. Since serifs serve to compensate ink spread and glare on the printed page, the opposite effect happens when transferred to screen, causing the serifs to become overemphasized.
Even though these differences would predict a lower speed for serif fonts, studies of fonts on screen usually show no measurable difference in overall efficiency. Serifs are slightly faster, meaning that the error rate increases proportionally to the speed increase. (Bernard)

So since serifs don't affect the objective experience (that is, the page to brain bandwidth), what does adding serifs do to the subjective experience? What is the personality of a font? There has been research on this specific topic, in a study by Dawn Shaikh, 40 different fonts were presented, and subjects rated each across 16 attributes. Included in the study were Georgia and Verdana. Both these fonts were designed for readability on the computer screen by Matthew Carter in 1993, they are very similar except that Georgia is a serif font and Verdana is a sans font. So by comparing their scores we can see what adding serifs does to the personality of a font without confounding variables. Georgia is beautiful, expensive, warm, and old while Verdana is cheap, cool, and young. Both are hard and stiff, but Georgia to a greater degree. Both are fast but Verdana is faster. So adding serifs is like putting on a tie: just slightly more formal.

Readability should not be confused with appeal. Frequently what looks best does not match what research shows is best, because the factors that influence efficiency are not conscious level factors. Studies that focus on appeal favor sans serif fonts, hence its use in logos and advertisements. Serif fonts appear more traditional (Stable, Practical, Mature, and Formal according to Shaikh, Chaparro, and Fox) and not as flashy.

Flashy is not better. As described by Warde, the choice of font is like a choice between a golden, engraved goblet and a crystal clear goblet. A person that actually cares about wine will choose the clear one because it exposes the wine, and one who does not will choose the gold because it is more expensive. So it is with typography. Good typography will be transparent and expose the words and ideas that they carry. Bad typography draws attention to itself. And so if a font is used enough, it is likely to be acceptable, even if only because seeing it is no surprise.

Lest one conclude that a popular font is appropriate in any situation, the Wall Street Journal gives the cautionary tale of comic sans (Steel). Designed in 1994 by Vincent Connare for use in comic bubbles (so that Microsoft could stop using Times New Roman for the task), the font was included as a standard font in Microsoft Windows. And from there it took on a life of its own. It has been seen on Disney ads, gravestones, and on retirement benefits documents with an 80 point “Important Papers Enclosed”. It has gained enough popularity to spawn a protest group, bancomicsans.com, complete with T-shirts displaying the message and stickers to place on offending uses. According to its manifesto, inappropriate use of the font is “analogous to showing up to a black tie-event in a clown costume”. Meanwhile Mr. Connare looks on with mixed disgust and amusement. “You can't regulate bad taste.” he says, “If you love it, you don't know much about typography, and if you hate it, you really don't know much about typography and should get another hobby.”

The best font depends on the message it carries. According to graphic designer Neville Brody, “The same message [can be] presented in 3 different typefaces. The response of that, the immediate emotional response, will be different and the choice of typeface is the prime weapon in that communication. Weapon because these days with commercial advertising the way the message is dressed is going to define our reaction to that message. If it says 'buy these jeans' with a grunge font, you would expect it to be some kind of ripped jeans, or to be sold in an underground clothing store. If you see that same message in Helvetica, [a sans font] you know it is probably on sale at Gap. It is going to be something that you can fit in that isn't going to stand out.”(Helvetica)

The choice of a serif font over a sans serif font should not be based on readability. Readability matters, the choice matters, but the choice should be based on what appearance is best for the message. A modernist or postmodernist message may find a common philosophy in a sans serif font similar to Helvetica, while another message may find more in common with the perceived stable, practical, and mature personality of serif fonts. Since these measures are the products of fashion, these studies will become obsolete, but currently serifs remain usable even on web pages.