To understand how type works, you must know how it is measured. Basically, typefaces are measured in two ways: height and width.
In earlier times when type was cast in metal, it was sold in discrete sizes that were measured in points. Today’s digital fonts can be enlarged or reduced by simply selecting, or specifying, a point size.
Originally, the term point size referred to the height of the metal body that held the characters. This was slightly larger than the distance from the highest to the lowest feature in the design.
A traditional point is approximately 1/72 of an inch or .01384 inch. With the advent of desktop publishing, the point became exactly 1/72 of an inch. Picas are another unit of measurement used for type; one pica equals 12 points, and six picas equal an inch.
This method of measuring is still used for digital type. Typefaces that have very long ascenders and descenders look smaller than other typefaces when both are printed at the same point size. This incongruity is illustrated below.
In addition to height, a typeface is commonly identified by its width. The width of a typeface is often expressed in the font’s style name, such as condensed or extended. Other expressions of width include compressed, expanded, and wide.
￼Variations on a Theme
A type family generally contains three variations on the regular face: italic, bold, and bold italic. However, many families have been designed to include variation in weight from ultra light to ultra black; variation in width from condensed to extended; multiple character sets, such as small capitals, titling capitals, swash capitals, oldstyle figures, alternates; and more.
This variety enables you to achieve just the look you want and allows for a good deal of flexibility. For example, it is often necessary to make a given amount of type fit into a predetermined amount of space on the page. When space is an issue, a condensed or extended version of a typeface can be a real lifesaver!