Graphics Reference
In-Depth Information
Line length and interline spacing
Line lengths on the display are best viewed
and perceived when viewed at a glance.
Readers scan text in chunks, establishing
fixation points throughout paragraphs. Sixty to
seventy-five characters per line is an optimal
number for ease of scanning websites. For
smartphone apps, thirty-five to fifty characters
per line is optimal.
Generous interline spacing is
recommended for displaying text on a
computer display. A reasonable guideline
suggests that the interline spacing equal 140
percent of the type size when typesetting for
websites. Measured in pixels, for example,
type with an overall height of 10 pixels
will require a measure of 14 pixels from the
baseline of one line of type to the baseline of
the next. This amount should be increased
by at least 20 percent for type on smartphone
apps. Ultimately, interline spacing must rely
on optical judgement and an experienced
designer's eye. As text settings get smaller on
screen, they require more interline spacing for
improved legibility (Fig.
8-20
).
8-20
Compare these four text settings. Lines of type
without sufficient leading inhibit onscreen legibility.
Weight and width
When letterforms appear too heavy or
too light on screen, they lose the visual
balance between form and counterform, a
critical relationship that enables readers to
distinguish one letter from another. This
principle holds true also for extremely
condensed and expanded letterforms.
Alignment
Flush-left, ragged-right text alignments are
easiest to read, whether implemented in
print or in electronic display applications.
Right-side line terminations quickly and
imperceptibly cue the reader from one line
to the next. Other text structures (flush-right,
ragged-left; centered; and justified) may serve
a viable purpose, but these alignments do
suffer a loss in legibility.
8-21
This landscape page from the website
Thinking for a Living promotes readability by
keeping paragraphs short and succinct, and by
creating a colorful narrative of the phases of the
moon. (Designers: Duane King, Ian Coyle, Shane
Bzdok, and Frank Chimero)
