Historically the setting of type for printing, known as typesetting, was a craft performed by experts trained in the rules of typography. These rules were derived from centuries of applied experience with considerations such as readability, composition and copyfitting. The advent of desktop publishing has changed the balance of expertise by shifting this responsibility to users more familiar with word-processing than typography. There are discernable differences between these two systems.

The application of the typesetting rules is still a sign of professional quality for both the designers and consumers of information. Though many of the differences are subtle, almost any reader will be aware of type that is well done—or poorly done—and its impact on the presentation of the message.

Listed below are several basic rules that may be useful as a guide for anyone wanting to improve the presentation of type. These are in routine use by designers and editors that produce our publications.

Basic Typographical Rules

Alignment
When aligning multi-column text blocks the copy should align across top of the columns. Bottom edges may be ragged, or unaligned.

Apostrophes
Use single closing quotation (’) mark to show the omission of letters or numbers. Add the letter s to the decade, not apostrophe s. For example: 1990s or the ’90s.

Dashes
Proper typography relies on three different types of dashes:

An em dash (—) is used to indicate a change in thought, or a break or interruption in a sentence. Generally there is no space on either side of the em dash.

An en dash (–) is used between paired numbers or words depicting a range, usually with a thin space on either side of it. It's like using the word to between paired figures or words.

Hyphens (-) are used only for hyphenating words or breaking words at the end of a line. Don't hyphenate words in a headline or title.

Readability
Use serif typefaces (Times as an example) for longer textual matter where readability is paramount. By design serifs are visual clues that make letterforms and words easier to recognize when reading.

Pay attention to leading, or line spacing, between lines of text. There is an optimum balance between the typeface, line length and line spacing that influences how easily type can be scanned when reading. Line spacing that is either too wide or too close can impair readability.

Avoid column widths that are either too short or too long. Similar to line spacing, column widths impact how easily type can be scanned when reading. Depending on the other type specifications, columns that are too narrow or too wide make the eye work harder and impair readability.

Smart Punctuation
When working in print always use “smart” quotes and apostrophes. In many word-processors the default marks for quotes and apostrophes is the same as for measures of feet (') and inches ("). Smart punctuation uses paired closing and opening marks (“quote” and ‘apostrophe’) that are different. These are sometimes referred to as curly quotes. The marks may be inserted manually by using the correct keystrokes or by setting the software to make this the default when typing. One exception to this rule is when setting type for Web pages. Due to complications of character coding between different systems, non-smart punctuation is frequently used for compatibility.

Spacing
Check for extra spaces after periods. There should only be one space between sentences. The two-space convention is left over from the typewriter era when all type characters were mono-spaced and had the same width, such as in the Courier typeface where a lowercase i is the same width as an uppercase M. In mono-spaced type the visual clue of an extra space helped the eye find new sentences. Desktop publishing has made proportional-spaced type the norm—where an i is much narrower than an M—and better letter spacing has eliminated the need for the extra space between sentences.

Check that all paragraph indents are equal. Vertical alignment and consistent spacing help preserve the hierarchy of information.

Generally, don't add extra space between paragraphs, but indent the first line of each paragraph instead. In some styles, such as for a Web page, a blank line may be inserted between paragraphs. In this case do not indent the paragraphs. In either case, to aid readability try to keep the overall line spacing consistent.

Widows and Orphans
Avoid leaving a word or portion of a word less than five characters in length at the end of a paragraph. This is called a widow.

Avoid beginning the top of a column with the last line of the preceding paragraph. This is called an orphan.

Both of these may be avoided by manually adjusting the letter, word or paragraph spacing prior to the widow or orphan. This will force the text to justify differently.