Since the introduction of computer fonts based on fully scalable outlines, a broader definition has evolved. Font is no longer size-specific, but still refers to a single style. Bulmer regular, Bulmer italic, Bulmer bold and Bulmer bold italic are four fonts, but one typeface.
Besides the character height when using the mechanical sense of the term, there are several characteristics which may distinguish fonts, also depending on the script(s) that the typeface supports. In European alphabetic scripts, i.e. Roman, Cyrillic and Greek, the main such properties are the stroke width, called weight, the style or angle and the character width.
Most typefaces are focused on the roman script and hence the regular or standard font is often labeled roman, both to distinguish it from bold or thin and from italic or oblique. The keyword for the default, regular case is often omitted for variants and never repeated, otherwise it would be Bulmer regular italic, Bulmer bold regular and even Bulmer regular regular.
Different fonts of the same face may be used in the same work for various degrees and types of emphasis.
The weight of a particular font is the thickness of the character outlines.
There are three basic categories of weights: light, normal, bold. There can be less weights in a typeface on the one hand and there can be finer differences, but there are never more than a total of nine font weights per typeface, three per group. Many computer fonts for office, Web and non-professional use come with a normal and a bold weight. If even this is not provided many renderers (browsers, word processors, graphic and DTP programs) support faking a bolder font by algorithmically increasing the stroke width.
The base weight differs among typefaces, that means one normal' font may appear bolder than some other normal'' font. For example fonts intended to be used in posters are often quite bold by default while fonts for long runs of text are rather light. Therefore weight keywords in their names may differ in regard to absolute position, e.g. bold usually is at the seventh of nine (virtual) positions, but sometimes at the sixth. The standard, regular font weight for most typefaces is slightly lighter than medium, i.e. it commonly is the fourth.
The ideal of nine font weights has lead to a numerical classification first used by Adrian Frutiger with the Univers typeface, although therein only ranging from 3 to 8. Later typographers introduced a larger scale from 100 through 900, available for instance in CSS, where virtual values 0 and 1000 can be assumed to represent no-ink and all-ink.
There are several keywords used to describe the weight of a font in its name, differing among type foundries and designers, but their relative order is usually fixed like this:
The terms normal, regular and plain, sometimes also book are being used for the standard weight font of a typeface.
In many sans-serif typefaces the characters of the italic fonts are only slanted (oblique), which is often done algorithmically, without otherwise changing their appearance. On the other hand there are typefaces with upright characters that take a more cursive form without a change in angle. For example the Cyrillic minuscule т may look like a smaller form of its majuscule Т or more like a roman small m as in its standard italic appearance; in this case the distinction between these styles is also a matter of local preference.
In Frutiger’s nomenclature the second digit for upright fonts is a 5, for italic fonts a 6.
The relation of the two Japanese Kana styles, called Katakana and Hiragana, is similar to European upright and italic difference, although their application is basically reverse, the cursive Hiragana being the standard to accompany Chinese ideographs (Kanji). Nevertheless they are not considered typographic variants of each other but separate character sets mapping to the same syllabary and sharing the same source, manyogana. The case of traditional and simplified Chinese glyphs is a different one, on the other hand, the latter being derived from the former and them not being used together in the same text.
There are other aspects that can differ among font styles, but more often these are considered immanent features of the typeface. These include the look of the minuscules, which may be smaller versions of the capital letters (small caps) although the script has developed characteristic shapes for them. Some typefaces do not include separate glyphs for the cases at all, thereby abolishing the bicamerality. While most use uppercase characters only, some exist that choose either the majuscule or the minuscule glyph at a common height for both characters (unicase).
Narrower fonts are usually labeled compressed, condensed or narrow. In Frutiger’s system, the second digit of condensed fonts is a 7. Wider fonts may be called wide, extended or expanded. Both can be further classified by prepending extra or the like.
Although most typefaces are characterised by their use of serifs, there are superfamilies that incorporate serif (antiqua) and sans-serif (grotesque) or even intermediate slab serif (egyptian) or semi-serif fonts with the same base outlines.