Typesetting – All About Space
Typography and typesetting is a game of controlling spaces, so its tools are all keyed to precise measuring. Because of the intimate scale in which typographic adjustments are made, type’s measurements have evolved independently of the coarser units used for other forms of craft or commerce.
Although the metricsystem has made some inroads into popular typographic practice—especially in Europe—type’s own unique measuring sticks are still the standard.
The measurements you use every day—whether they’re inches and feet or centimeters and meters—are fixed, or absolute, measurements. That is, an inch is always an inch and a meter is always a meter. Type has its own equivalents, which are the pica and its subdivision, the point.
The modern point used as a standard today in almost all typesetting systems is relatively new, having been created by Adobe Systems in the course of developing the PostScript page description language.
The height of type is measured in points, and the width of a letter or a line of type is measured in picas. Point size is the height of the body of a letter in a typeface; originating in metal type, it was a slug of lead the typeface was set upon. The width of a typeface is measured in characters per pica.
Most type is available in sizes ranging from 5 points to 72 points. Type that is 14 points and less is used for setting text and is called text type or body copy. Sizes above 14 points are used for display type.
Line length, which is the horizontal length of a line of type, is measured in picas.
Approximately 6 picas = 1 inch; 12 points = 1 pica; approximately 72 points = 1 inch.
Determining a suitable line length for readability depends on the design of the specific typeface, type size, line spacing, and length of the content.
A designer measures type as well as the spatial intervals between typographic elements.
These intervals occur between letters, between words, and between two lines of type.
- The spatial interval between letters is called letterspacing
- Adjusting the letterspacing is called kerning
- The spatial interval between words is word spacing
- The spatial interval between two lines of type is line spacing, traditionally called leading in metal type, where strips of lead of varying thickness (measured in points) were used to increase the space between lines of type
Many people still use the term leading to mean line spacing:the distance between two lines of type, measured vertically from baseline to baseline.
In metal type, letterspacing and word spacing are produced by the insertion of quads—metal blocks shorter than the type height—between pieces of metal type.
The Em in Typesetting
The fundamental relative unit in typography is the em. An em is the same size as the type currently being set, so if you’re setting 11-point type, an em equals 11 points. Despite the sound of its name, an em is not the width of an M; in fact, an M is rarely a full em wide.
Em-based White-Space Adjustments
The spaces between letters are also measured in relative units: fractions of an em. This assures that if, for example, 12-point type is resized to 14-point, any spaces between characters that have been adjusted will also be resized proportionately, and those adjustments will be correct at the new type size. One such adjustment is kerning, the adjustment of spacing between particular letter pairs to correct problems arising from the shapes of those letters. The letters in To, for example, are usually kerned closer together, because the empty space under the crossbar of the T creates a gap between it and the o next to it.
Likewise, rn in some typefaces have to be kerned apart to avoid having them look like an m. Digitally generated typefaces generally have tables of kerning information built into them – which can be adjusted by the designer.
Have fun kerning and learning with this game: http://type.method.ac/
- Bringhurst, Robert (1992). The Elements of Typographic Style. Hartley & Marks. pp. 25–26
- Spiekermann, Eric ()2002) Stop Stealing Sheep & Find Out How Type Works. 2nd ed. Peachpit Press
- Strizver, Ilene (2013) Type Rules: The Designer’s Guide to Professional Typography. Wiley