Learning typographic usage may seem like the simple application of common sense and visual sensibility, especially when it comes to rudimentary typographical practice, however it’s not so straightforward. There are volumes of research that have been generated about the readability, legibility, and visibility of typography as it applies to paragraph bodies of text in theory as well as in practice.
The following text "don't and do" samples demonstrate a number of basic principles that are essential for setting text that performs suitably in paragraphs with the potential to be as aesthetically pleasing as conditions will allow. The statement used in the examples below is an excerpt from a treatise on typography written in 1818 titled Annals of Parisian Typography, by William Parr Greswell.
Widows
Don’t allow a single word line or “widow” to occur at the end of a paragraph.
Do alter paragraph line endings to change the “rag” and eliminate a widow.
Indention
Don’t indent the first line of an article or chapter.
Do remove the indentation. A first paragraph should not be indented. Paragraphs following the first should be indented.
Coloration
Don’t use a color for text that is difficult to read.
Do choose a text color with adequate contrast to the background.
Typestyles
Don’t choose a display font style that is difficult to read.
Do use display fonts sparingly for short statements or portions of a statement.
Capitals
Don’t set paragraph text in all capital letters.
Do use all capital letters for single words, single sentences, or short statements.
Ornamentals
Don’t use fonts with ornate capital letters for all cap statements.
Do use ornate capital letters only at the beginning of sentences.
Weight
Don’t choose excessively bold fonts for long bodies of text.
Do choose reduced weight fonts for paragraph use.
Linespacing
Don’t set text solid or use negative line spacing.
Do add space between lines or use default spacing for the point size in use.
Wordspacing
Don’t use an excessive amount of word space for paragraph text.
Do use default or slightly reduced spacing.
Letterspacing
Don’t use an excessive amount of letter space for paragraph text.
Do use letter spacing in a moderate amount.
Measures
Don’t set text in long lines or “measures”.
Do limit the average length of lines in a paragraph to no more than 12 words.
Justification
Don’t set type flush on both sides or “justified” in short measures.
Do set type as justified in wider measures.
Rivers
Don’t allow auto justification to create "rivers and lakes".
Do manually adjust justified text to improve rivers.
Flush Right
Don’t set a chapter or story flush right, ragged left.
Do use flush right, ragged left for shorter statements or call outs.
Centering
Don’t set a chapter or story as centered text.
Do use centered text for shorter statements or call outs.
Hyphenation
Don’t allow excessive hyphenation to occur in a paragraph.
Do change the rag so that no more than two adjacent lines are hyphenated.
Condensing
Don’t excessively compress a font horizontally.
Do use original letter proportioning or find a font designed to be condensed.
Extending
Don’t excessively vertically compress a font.
Do use original letter proportioning or find a font designed to be extended.
Verticals
Don’t letterset type vertically.
Do set words in vertical columns, but only sparingly if necessary.
Outline
Don’t use outline type for large bodies of text.
Do use outline type for short statements or contrast, but only sparingly.
Modification
Don’t apply excessive visual effects to paragraph text.
Do use visual effects subtly and with restraint.
Overprinting
Don’t set dark type over images with detailed or contrasting elements.
Do lighten or “dodge” the image to improve the readability of the text.
Don’t set white type over images with detailed or contrasting elements.
Do darken or “burn” the image to improve the readability of the text.