The term "desktop publishing" usually refers to the process of creating and
printing out a document from one's computer; "desktop publishing" is
generally held to have begun when, especially on the Mac, computer users
were first able to pick out fonts for a document and print that document
from the comfort of their homes and offices. No longer was publishing
limited to those with access to a printing press!
But actually, students, secretaries, and other amateur typographers had been
producing print documents from their desktops for nearly a century before
the term "desktop publishing" was coined. They used a little device called a
The typewriter, unlike the printing press, was a one-trick pony. It had one
monospace font, in one size, one weight, one style. Typewriter text was less
typographically expressive than traditional printed text that could be
kerned and italicized; the lack of italics was a particular problem. How to
indicate emphasis for a word, or properly style a book title in a citation?
Typewriters borrowed a convention from editors' proofreading markup: an underline
indicates "this should be italicized". Underlines were easy enough to add to
typewriters, and so all the style manuals written for twentieth-century
typists indicated that an underline was the proper way to indicate a
title, or to add emphasis.
Meanwhile, the typewriter's monospace font made the space between sentences no larger
than any other space in the text; in printing, the proportional font allows
for a slightly larger space at the end of a sentence. And so another hack
was developed for typewriters: when you come to the end of a sentence, put
two spaces after the period rather than just one. This and many other
typewriter-specific rules became standards in style manuals, and in the age
of the typewriter, they were the best solution available for the student or
office worker who wanted to be able to produce readable documents from a
relatively cheap, mechanical desktop machine.
At first, computers only printed out monospace characters, and the old
typewriter customs still made sense. But upon the advent of so-called
"desktop publishing", the typist could also act as the typographer; and
unless you had some sort of sick Courier fetish, you would design and print
your documents with the full benefits of a proportional font that had an
italic, or at least an oblique, style available. Goodbye, extra spaces!
Goodbye, hideous underlines!
Technology emerged from the dark ages of the typewriter, but many typists
have not. Those who learned to type on a typewriter, or who learned to type
in the old style of the typewriter, have these peculiar habits. They
double-space after a period, they use underlines, they attempt to center
text with tabs and spaces, they feel an urge to hit 'return' at the end of
each line. And if they are designing proportionally typeset paragraphs, they
Putting two spaces after a period, in a proportional font, is unnecessary
and in some fonts may make the text harder to read (although in HTML, unless you
have a cruel WYSIWYG editor that adds extra non-breaking spaces, your double
space is mercifully converted to a single one). Underlining disrupts the
appearance of text, impairs readability, and sends typographers and graphic
designers into fits of agonized screaming. ("The ugliness! The ugliness!")
On the web, the underline has a special purpose: identifying links. Not
everybody uses underlines on their links, of course, but it is a widely
recognized convention. For this reason, the underline is acceptable to some
people who otherwise would hate it; but more importantly, underlined text
that is not a link is very confusing, and should be avoided for this reason as well.
For the moment, I'll ignore the other differences between printed and
nscreen text; there are other factors that come into play. But for a
general guide to un-learning typewriter conventions to make for better
computer typography, check out A. Cemal Ekin's Typewriter
Days: A Bygone Era That Won't Go Away (pdf) at http://www.providence.edu/mkt/ekin/toptips/layout_guide.pdf