Stroke weight
Width of the lines which make up the font. Many serif fonts use different
weight strokes, such as the right half of the Times Roman letter “U” being
thinner than the left half. On the other hand, most modern sans serif fonts
are mono-weight, meaning the lines forming the letter are all the same
weight, such as with Arial.
x-height
Height of lowercase letters measured from the baseline, excluding
ascenders and descenders, as in “x.”
Figure xx. Typography terms.
Serif versus san serif
The two main categories of font types are serif (with the little tails on the letters) and sans serif
(without the little tails). The serifs are suppose to help guide the eye along the row of text and
enhance reading.
In the U.S., body text is typically set in serif fonts; European readers often see san serif body
fonts. The reading speed and comprehension research finds little differences between two as long
as a reasonable font choices are made. Researchers do consistently find a preference in US
readers for serif, but attribute it to familiarity with the typeface. In a interesting contradiction,—
but one that is rather common in the usability literature—Bernard et al., (2002) found that
Verdana was the most preferred font, while Times was the least preferred for online reading.
However, they also found that Georgia and Times serif fonts are considered more attractive. In
other words, people thought Times was more attractive, but wanted to read text formatted with
Verdana. Contradictions such as these reveal the importance of usability testing with real users
and not basing designs on either design rule-of-thumb or asking people which they prefer. Their
preferred choice may not be the best choice for comprehension. Likewise, Brumberger, (2004)
found typefaces do have persona which they impart on the text, but that persona does not have a
significant impact on either comprehension or reading time.
For print (at least in the US), there is general agreement to use serif for a body font and sans serif
for headings. However, there is an ongoing debate about whether or not to use serif or sans serif
fonts for online text since computer monitors have trouble properly displaying a serif because of
the relatively (compared to print) low resolution. The lower resolution of a monitor causes the
serifs to display poorly. “One reason for this could be that at smaller font sizes on computer
screens, the serifs stop acting as distinguishers and start becoming visual 'noise'” (Bernard &
Mills, 2000). The argument is that that the width of a serif cannot be less than one pixel and
always comes in full pixel increments, but the strokes of the font may also only be one pixel,
thus the serif width is the same size as the stroke widths. While some specialty fonts may have
this design as part of the standard font, the common fonts such as Times Roman and Garamond
do not. There serifs are designed to be much smaller and narrower than the stroke widths. This
same argument applies to display of unequal stroke widths common in serif fonts, where the
monitor has a difficult time properly displaying the varying line width. Modern LCD monitors
are improving on their ability to display serifs and the serif/sans serif debate for online
information may soon be passé.
While designers continue to debate the serif/sans serif online issue, research on reading speed
and individual preferences is mixed. Although reading speed may be slower on a monitor than
paper, the serif and sans serif reading speed on a monitor tend to be about the same. In an online
study, reading efficiency is the same for serif and sans serif fonts, but serif fonts read faster
(Bernard, Lida, Riley, Hackler & Janzen, 2002). On the other hand, with printed close-set type,
close-set type there was no different in reading speed (Moriarity & Scheiner,1984) between serif
and sans serif. Studies have found serif fonts to promote greater reading comprehension than
sans serif fonts, such as Arial. For example, a study by Boyarski, et al., (1998) found small but
significantly higher levels of comprehension for a serif font (Georgia) over a sans serif font
(Verdana).
For small type or text with lots of numbers, sans serif fonts are the most readable.
Font size
Not surprisingly, larger text sizes are perceived to be more readable than smaller sizes (Mills &
Weldon, 1987; Rudnicky & Kolers, 1984). However, any actual readability differences are often
not significant until the size difference become larger than would normally be consider in font
choices (Tinker, 1963). For example, finding a readability difference may require comparing a
12 pt and 24 pt font, but design teams essentially never face of choice of having to pick between
12 pt or 24 pt font sizes. Bernard et al., (2002) believe these results should also be true for online
reading. A conclusion in agree with Chadwick-Dias, McNulty & Tullis (2003) who found text
size on a web page did not significantly affect performance in any age group
Word legibility seems to moderately increase up to a 12 pt type size. Although reading speed
does not seem to be significantly impaired by smaller sizes, the reader does suffer visual fatigue
if forced to read long passages in small type (Tinker, 1963). Tinker claims that for body font text
in print, 9-12 point fonts with 2 points of leading will all have essentially the same reading
speed. For online text 12-point size were read faster than fonts at the 10-point size (Bernard, et
al., 2002).
Eye tracking studies show larger font sizes are read slower than 10-12 point type. The area seen
by the eye does not change, but the amount of type seen at a glance decreases. This increases the
amount of cognitive effort required to put the words together.
Guidelines for choice the font size.

For most general audiences, font size at 10–12 points is good.

For a predominantly older readership of 65 and over or for audiences with known
visual handicaps, use a body text font at 14–18 points. Consider how many greeting
card companies and Reader’s Digest offer large print versions.

For young children or beginning readers of any age, a type size around 14 points in
san serif is best (Bernard et al, 2001).
Although these guidelines give rules in point, the actual and apparent size of fonts can vary
greatly. Figure xx shows font that are the same size, but display very different actual heights.
Font choices need to be tested with the intended readers.
Figure xx. Variation in actual height of fonts sizes. All fonts shown are 40 points, but the
height of the capital letter varies.
Kerning and tracking
Kerning is the adjustment of space between pairs of letters. Tracking is the adjustment of space
for groups of letters and entire blocks of text. Excessively tight or loose tracking causes
readability problem since it makes the words harder to distinguish (figure xx). Very tight kerning
is useful for special effects, such as logos where the letters are touching. For example, in the
FedEx and IBM logos, the letters all but touch.
People read faster with close set type than with regular set type. Reading speed was the same
with serif and sans serif (Moriarty & Scheiner, 1984). The justification is that with close set type,
more letters can be seen within the fixation area. However, this study was only with reading
speed over a short time period and did not attempt to measure comprehension.
The proper use of tracking lets the text fit properly onto the page with minimal hyphenation and
orphans. The tracking is used to adjust text to prevent widows and orphans, but at times the
change is excessive. The design team needs to ensure text adjustments made for a paragraphs
appearance do not reduce the overall readability.
Figure xx. Example of different font tracking. Settings here are expanded or condensed 1.1
pts versus Microsoft Word’s default of 1.0.
Paragraph layout elements
The previous section looked at various aspects of a typeface itself. This section looks at the
typographic factors that affect how a typeface is set in longer blocks of text. Good layout results
in higher satisfaction and less mental fatigue than poor designs (Chaparro, Shaikh, & Baker,
2005).
Leading
Leading is the space between the lines of text (also called line spacing). The guideline for normal
body text is to have leading equal to 20% of the font size. Long lines of text need more leading.
Vertical spacing effects how people perceive online text. They seem to prefer a larger amount of
vertical space than is standard for web browsers (Holleran & Bauersfeld, 1993), but reading
speed and comprehension seem to be relatively unaffected unless taken to an extreme (Chaparro,
Shaikh, & Baker, 2005).
Line lengths
The line of text should be about two alphabets (52 characters) long for best reading. Research
into the relative legibility of different line lengths in print has led to recommendations that line
lengths should not exceed about 70 characters per line.
Most articles tend to claim longer or shorter lines will slow down reading speed. For longer lines,
the eye often gets lost during the return to the next line. If the lines are too short, readers cannot
make use of much information in each fixation and there is significant time lost as the eye is
constantly having to return to the next line (Rayner & Pollatsek,1989).
Line length has also been found to affect reading rate online. Dyson and Haselgrove (2001)
found the length for best compromise between reading speed and comprehension was 55
characters, comparable to that for print. Longer line lengths do seem to be read faster (Dyson &
Kipping, 1998; Shaikh, 2005). Shaikh found lines with 95 characters read the fastest, but the
readers preferred shorter lines. On the other hand, 95 characters was her longest line, but reading
on paper could easily have a longer line. A portrait-formatted page with .5 inch margins contains
90–95 characters; pages formatted landscape would greatly exceed that length and cause reading
trouble.
Type alignment
The most readable alignment is left justified, ragged right. It provides a distinct visual
appearance to each page based on the line breaks. Fully justified text, although used by many
book and magazine publishers, does not provide that visual distinction. Left justified, ragged
right text also provides the most consistent word and character spacing. Fully justified text often
has to use overly tight or loose tracking to align the text.
Centered or ragged left, justified right texts are difficult to read since they do not provide a
consistent left margin for the eye flyback to return to. They should be used only as special
formatting and not for body text or any blocks of text more than a few lines long.
Background contrast
The eye distinguishes the text based on the relative contrast between the foreground and
background. Reducing that contrast makes the eye work harder which lowers reading speed and
comprehension.
The color used for the background also has a significant effect on the legibility. A study of which
looked at slides displayed on a computer screen found reading speeds were highest for color
combinations with high contrast between the letters and backgrounds (Garcia & Caldera, 1996).
Black-on-white, yellow-on-blue, black-on-gray, and yellow-on-black were read significantly
faster than other combinations.
Based on the lighting, the legibility of the text can change. With lower light levels, the font must
be larger for a person to distinguish it. The background contrast also plays a major role in
legibility with smaller fonts being more legible on a high contrast background (figure xx).
Figure xx. Legibility with different font/background contrasts. Text is 12 pt Time Roman
with the background shading increasing by 20% per step from 0-100%.
Reversed out text
Reversed type is a lighter typeface on a darker background (figure xx). The large dark area easily
draws the eye to it. Reversed type works well for a headline, but not large blocks of text. Black
fonts on a light background are more legible than white fonts on a black background (Taylor,
1934; Scharff & Ahumada, 2003).
Advertising research has found ads with large revered areas are rated as less visually appealing
and rated as harder to read. Ad Effectiveness: "What Affect Does Reverse Type have on an
Ad?" The Readex Review, Memo 11, Copyright 2001
Reversed text is read about 10% slower and requires more eye fixations (Tinker, 1963). Reversed
type can be harder to read since the ink can spread into the white areas of the reversed type. With
normal black on white printing, the ink spreads out and makes the letter wider, with reversed
text, the ink spreads in and makes the letter smaller. The ink spread is most pronounced with
serif type since narrow serifs can handle very little spreading before looking jagged or broken.
The broken appearance makes the page look bad. The large dark area slows down reading. In
general, reversed text should be done with larger sans serif fonts and the lines should have
increased leading.
Figure xx. Reversed type. Notice how the 10 pt lines of (Times Roman) serif and (Arial)
sans serif read differently as the black visually bleeds into the serifs. Use of modern serif,
with their small serifs would exacerbate the bleed problem.
Typeface and emotion
High quality HII ensures that any emotional elements within the text fits the information being
communicated. The typeface in a presentation carries with it an emotional element that affects
how the audience responds to a text and what they learn from it (Larson, 2004). Kostelnick
(1990) points out that that the typography carries a “visual texture, tone, and mood,” that
“suggests a rhetorical stance: serious, conversational, low key, energetic, highly technical, or
user friendly” (p. 199). Essentially every book on typography or desktop publishing discusses
typeface personality, although they don’t always use the term ‘personality’. For example,
Kostelnick and Roberts (1998) claim that typefaces are perceived as having an emotional state,
such as serious, funny, formal, friendly, personable, or technical. Likewise, Parker (1997) and
Shushan and Wright (1994) discuss how a typeface conveys mood, communicates attitude, and
sets tone.
Typeface personality comes from both the typeface anatomy and its context, since long use of
certain typefaces in certain contexts has connected them in people’s minds (Mackiewicz, 2005).
For example, use of cursive or Old English fonts for invitations. The full typeface personality is
not a instant or pre-defined attribute, but rather an emergent one which arises from reading a text
with a particular typeface within the overall context of the document, as Brumberger (2004)
explains:
The data emphasizes that typefaces and texts interact during the reading process,
countering the notion that a typeface with a particular persona will lend that
persona to any document. Although a group of readers may consistently assign
particular personality attributes to a particular typeface, that typeface may not
consistently color every text they read in the same way. Thus, the project
reinforces the notion of technical communication as rhetorical problem solving
(Flower 1989), in which context is crucial and each communication situation
requires a carefully considered and appropriately tailored solution (p. 22).
In general, each typeface has a distinct persona and the design team must match that persona
with the text. In ongoing design battle, some designers want to pick fonts based on their
appearance to add interest, while others argue for using standards such a Arial or Times Roman
to privilege easy-to-read or what the reader is comfortable with even if they are boring. Working
against the latter idea, Mackiewicz (2005) found that fonts perceived as comfortable-to-read are
not necessarily perceived as “plain” or “boring.” She found that Gill Sans and Souvenir Lt were
rated high on all three scales she test for: comfortable to-read, attractive, and interesting. Her
findings on the interesting variable suggest that audiences are ready for fonts that break from
default settings and old standards. Of course, design teams need to test their font choices, but
other fonts besides the basic standards of Times Roman and Arial can be effectively used
(Mackiewicz, 2007a).
Brumberger (2003a, 2003b, 2004) has performed the most extensive examination of how a
typeface carries with it an emotional element and how people react to that emotional element.
Figure xx show some of the typefaces she examined and how they were perceived. Concluding
her review of past research into typeface appropriateness, Brumberger (2003a) states “each of
these studies demonstrates readers’ awareness of typeface appropriateness and their ability to
make judgments regarding the appropriateness of typefaces for a specific purpose or text” (p.
225). Of note, she found readers expect the emotional element to match the tone of the text and
any mismatch causes some level of cognitive dissidence.
Figure xx. Typeface persona (adapted from Brumberger, 2003b, p. 214)
While Brumberger dealt with a wide range of typefaces, even research of common typefaces and
staying within a serif or sans serif font style, Tantillo, DiLorenzo-Aiss, and Mathisen (1995)
found significant differences in how people perceived a font. When students were asked to
evaluate six typefaces (Avant Garde, Century Schoolbook, Goudy Old Style, Helvetica, Times
New Roman, or Univers) using 28 variables, the three sans-serif typefaces were rated
significantly different from the three serif typefaces on many of the variables. Serif fonts were
rated as more elegant, charming, emotional, distinct, beautiful, interesting, extraordinary, rich,
happy, valuable, new, gentle, young, calm, and less traditional than the sans serif type styles.
They summed up the finding by concluding that sans serif styles were perceived as more
readable and less legible than the serif styles. This research used common typefaces which
readers should see and read with some regularity, yet they have significant differences in how
they were perceived. Design teams need to careful consider the impact of the font choices on the
text and not pick based on a designer’s favorite or simply falling back on Times Roman or Arial.
One piece of helpful research, Mackiewicz (2005) found that examining only five of the letters
within a font—uppercase J and lowercase a, g, e, and n letterforms—gives enough information
for a design team to make decisions about the font emotional attributes and to determine if the
font is appropriate for the document.