Setting a paragraph somebody can read

Three numbers decide almost everything

Size, leading, measure. Get these right and mediocre type looks competent. Get them wrong and no amount of typeface choice rescues it.

• Size. Body text in a book or brochure is 9 to 11 pt. In a wall-mounted notice it is whatever is legible at the distance. On a phone it is 16 px, because that is the browser default for a reason.
• Leading: line spacing, measured baseline to baseline. Start at 120 to 145% of the size. 10 pt type takes 13 or 14 pt leading. The looser end for a long measure or a large x-height face, the tighter end for short lines.
• Measure: the line length. 45 to 75 characters, counting spaces. Below 45, the eye jumps back too often and the rag gets ugly. Above 75, the return sweep loses its place and readers skip lines.

Measure and leading interact: a long measure needs more leading, because the return sweep is longer and the eye needs a clearer target.

To count your measure without counting: set a line of lowercase alphabet twice: abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz. Roughly two and a half alphabets is the right column width.

Ragged right or justified

Ragged right: one word space everywhere, uneven right edge. Almost always the better choice, and always the better choice at a narrow measure.

Justified: word spaces stretched to fill each line. Requires hyphenation on, and requires a measure long enough that stretching a few spaces is not visible. Justified text at a 45-character measure produces rivers: vertical channels of white running down the paragraph, which you see instantly once you have been told to look.

If you justify, set the H&J values rather than accepting the defaults. In InDesign, Paragraph panel ▸ Justification:

• Word spacing: minimum 80%, desired 100%, maximum 133%
• Letter spacing: minimum 0%, desired 0%, maximum 4%, never more; stretched letterspacing in body text is worse than an uneven rag
• Glyph scaling: 98/100/102% at most

InDesign’s Adobe Paragraph Composer looks at the whole paragraph rather than one line at a time and produces markedly better justification than the single-line composer. It is on by default in recent versions; check, because it is the largest single improvement available for free. Scribus has no equivalent; LibreOffice has none; LaTeX has had one since 1982 and is still the best justification available anywhere.

Fixing a rag

A good rag is a soft, irregular wave. Bad rags have shapes:

• A ladder: three or more consecutive lines ending in a hyphen. Limit consecutive hyphens to 2.
• A wedge: lines getting steadily shorter or longer, which reads as a deliberate shape and is not.
• A hole: one very short line beside long ones.

Fix with a discretionary hyphen (Ctrl+Shift+-), a non-breaking space (Ctrl+Alt+Space) to keep a short word with its neighbour, or by editing the copy. Never fix a rag by tracking one paragraph; the change in colour is more visible than the rag was.

Widows and orphans

• An orphan is a lone first line of a paragraph stranded at the bottom of a column.
• A widow is a lone last line carried to the top of the next column, or, in the stricter sense, a single word alone on the last line of a paragraph.

Set Keep Options ▸ Keep with next: 2 lines, and start/end lines minimum 2. In Scribus this is in the paragraph style’s Distances and Alignment. Fix a single-word last line with a non-breaking space between the last two words.

Optical margin alignment

Punctuation and the round or diagonal parts of letters make a left or right edge look ragged even when it is mathematically flush. Optical margin alignment hangs quotes, hyphens and the overhang of o, T and W slightly outside the column so the edge looks straight.

InDesign: Story panel ▸ Optical Margin Alignment, set to the type size. It is one checkbox, it is free, and it is the difference people notice without being able to name.

The free path

Scribus does styles, H&J, keep options and hyphenation properly, and is capable of a well-set book. LibreOffice Writer with real paragraph styles will set a readable novel interior. LaTeX sets the best justified text of anything on this list and is the hardest to control visually. All three are free; the thing you cannot get for nothing is Adobe’s paragraph composer and optical margins.