A typeface design is not complete without sensitive adjustment of letter spacing through the use of kerning and tracking tables.
Kerning is the adjustment of individual letter pairs. Its purpose is not to tighten letter spacing overall but to remedy problems which occur between specific letter pairs.
The first example below shows unkerned pairs, and the second line has kerned pairs.
Tracking is the uniform addition or subtraction of letter space to/from all the characters in a font. Tracking generally is used to increase letter spacing as type gets smaller and decrease it as type gets larger.
In the first sample, tracking is off; in the second tracking is on, increasing letter spacing.
At this size, tracking is the same off or on.
In the first sample, tracking is off; in the second tracking is on, decreasing letter spacing.
The kerning tables that come with a font are often cursory and poorly done. They are designed to be used at the master point size, usually 12 point, and do not include kerning of numbers. For a large design project, it is therefore best to create custom sets of kerning and tracking tables for the specific fonts and sizes used in that book. Numbers and punctuation should be included in kerning tables. It is sometimes necessary to have separate kerning tables for the same font if it is used both in text and large display sizes. Simply adjusting tracking to account for size changes usually produces awkward letter pairs in either the large or small sizes.
Kerning pair tables should be appropriate to the typefaces letter forms and history. An oldstyle (metal) face, Garamond 3, for example, calls for more open letter space than an advertising (photo) face such as ITC Garamond. Adrian Frutiger was once heard complaining about the tightening of his face, Univers, in the printed program for a conference at which he was speaking. He said that he had designed the face to set looselythe letter spacing was part of the design. However, he had no objection to using a kerning pair table to make the spacing more uniform, as long as it didnt tighten the letter spacing and change the overall look of the font.
Letter spacing should be considered in relation to the individual character widths of the typeface used. Generally, condensed faces should be set tighter than expanded faces. Visually, a wider character seems to need more side bearing (space left and right of the character) than does a condensed character. This is not necessarily the case in display use; witness the recent popularity of setting Univers extra condensed with added letter space.
The first example shows default letter spacing and the second shows reduced letter spacing.
The first example shows default letter spacing and the second shows increased letter spacing.
Letter spacing should be increased in copy which is set all caps or small caps. If small caps are used for the first few words of a paragraph, a common practice in art books, the small caps should have more letter space than the words that follow them.
The first example is set normally; the second has added letter space.
The first example is set normally and the second has added letter space.
Here is a small caps intro.
The computer has brought about the use of display typefaces at small sizes. Many postscript fonts were digitized from large [metal] master art designed to be used at 24 point or above. The type designer had only the use of large sizes in mind and accordingly built less letter space into the designs. Therefore, letter space should be added to display faces when used in text sizes.
The first example shows default letter space, the second shows added letter space.
Letter space should not vary in copy which is set ragged left, right or centered. This problem has only arisen recently because of poor default settings in some desktop publishing programs.
Variation in letter space is not ideal when setting justified copy but is sometimes necessary, when justifying on a narrow measure, to avoid large gaps of word space. However, narrow columns are more common in newspaper and magazine work than in museum publications.
The example on the left shows narrow measure copy without added letter space; the right shows it with added letter space.