Leading

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"Leads" redirects here. For the city and metropolitan borough in West Yorkshire, England, see Leeds. For other uses, see Lead (disambiguation).
"Line leading" and "Line lead" redirect here. For the water navigation concept, see Leading line. For other uses, see Lead line (disambiguation).

In typography, leading /ˈlɛdɪŋ/ refers to the distance between the baselines of successive lines of type. The term originated in the days of hand-typesetting, when thin strips of lead were inserted into the forms to increase the vertical distance between lines of type. The term is still used in modern page layout software such as QuarkXPress and Adobe InDesign.

In consumer-oriented word processing software, this concept is usually referred to as "line spacing" or "interline spacing."

Origins[edit]

The word comes from lead strips that were put between set lines of lead type, hence the pronunciation "ledding" and not "leeding". When type was set by hand in printing presses, slugs or strips of lead of appropriate thicknesses were inserted between the lines of type to add vertical space, improving legibility.

Text set "solid" (no leading) appears cramped, with ascenders almost touching descenders from the previous line. The lack of white space between lines makes it difficult for the eye to track from one line to the next, makes rivers more obvious, and hampers readability.

Examples[edit]

This block of text has default leading:

Typography (Greek: typos "form", graphein "to write") is the art and technique of setting written subject matter in type using a combination of typeface styles, point sizes, line lengths, line leading, character spacing, and word spacing to produce typeset artwork in physical or digital form.

The same block of text set with 50% leading is easier to read:

Typography (Greek: typos "form", graphein "to write") is the art and technique of setting written subject matter in type using a combination of typeface styles, point sizes, line lengths, line leading, character spacing, and word spacing to produce typeset artwork in physical or digital form.

The same block of text at 100% leading is again harder to read and makes less efficient use of vertical page space:

Typography (Greek: typos "form", graphein "to write") is the art and technique of setting written subject matter in type using a combination of typeface styles, point sizes, line lengths, line leading, character spacing, and word spacing to produce typeset artwork in physical or digital form.

On the World Wide Web[edit]

In CSS, leading is implemented by creating a difference between the content height and the value of the line-height property. Half the leading is called the half-leading. User agents center glyphs vertically in an inline box, which adds half-leading on the top and bottom. For example, if a piece of text is "12pt" high and the line-height value is "14pt", 2pt of extra space should be added: 1pt above and 1pt below the letters. (This applies to empty boxes as well, as if the empty box contained an infinitely narrow letter.)

Feathering[edit]

The leading may be increased to align the bottom line of text on a page in a process known as feathering,[1] carding, or vertical justification.

References[edit]

  1. ^ Eckersley, R.; et al., eds. (1995). Glossary of Typesetting Terms. Chicago: University of Chicago Press. ISBN 1-281-43121-4.