Glyph

Sources
Further links

General

When we speak about characters we assume two things: the image that we see and the symbolic information that relates to this image. The specific form (shape) of a character is called a glyph: Same character with different glyphs:

A glyph is the minimal unit of font information. Each glyph can be defined in two ways: information about the character the glyph represents and specific information about the glyph. For example, we can define the character “H” as “two vertical strokes with one horizontal stroke that connects them at half their height.” All possible shapes of the character H can be defined this way. To get a glyph definition, we would add the following words (for the Times typeface): “The vertical strokes are wider than the horizontal strokes and each of them is finished by thin rounded serifs.”

Meaning of glyphs

The same image may have many meanings. For example the character “H” means one letter in the English language and a very different letter in the Russian language (very close to an English “N”) or in the Greek language (Eta).

Features of glyphs

Although the Chinese have invented moving letters long before Gutenberg not much is known about form variations for non-latin scripts. For latin scripts (and derivatives such as cyrillic) letterforms got many features. The names of the different parts of a character have a long and well documented history. There are manuscripts going back to the 15th century. The most used terms are listed in the image and table hereafter.

	Description of feature
1	horizontal stroke that is free on one end	Arm	Arm
2	part of the lowercase letters b, d, f, h, k, l and t that extends above the x-hight	Ascender	Oberlänge
3	horizontal stroke in the letters A, H, e, t and similar letters	Bar
4	curved stroke which makes an enclosed space with a character	Bowl
5	fully or partially enclosed space within a character	Counter	Punze
6	part of the letters g, j, p, q, y and sometimes J, that extends below the baseline	Descender	Unterlänge
7	small stroke projecting from the top of the lowercase g	Ear
8	a thin stroke usually common to serif typestyles	Hairline
9	the stroke connecting the top and bottom of a lowercase g	Link
10	lower portion of lowercase g	Loop	Schlaufe
11	a line crossing the main strokes of a character. There are many varieties	Serif	Serif
12	descender of Q or short diagonal stroke of the R	Tail
13	the end of a stroke not terminated with a serif	Terminal
14	curved stroke of the h, m and n	Shoulder
15	main curved stroke of a lowercase or capital S	Spine
16	a small projection off a main stroke; found on many capital G's	Spur
17	straight vertical stroke, or main straight diagonal stroke in a letter which has no vertical strokes (x, X, z, Z)	Stem	Stamm
18	direction of thickening in a curved stroke	Stress
19	straight or curved line	Stroke
20	fancy flourisch replacing a terminal or serif	Swash
21	relation between thin and thick strokes (pole or equatoral position in round glyphs)	Contrast

Interpretation of glyphs

In hot-metal times the term glyph was not yet used. A letter was the physical representation of a character: a block of metal with the cut out mirrored image of the letter shape.

With the advent of electronic printing, the variety of shapes for a chacrater proliferated – because it became much easyer to create and modify shapes. The glyph is described as an outline from which various process-dependent forms can be derived. For most printing processed the outline is transformed into a bit-map ➔ rendering, rasterising.

Special glyphs

At least in the western typographic world special forms have developed:

	Fleuron
	Grammalogue (Literally, a letter word; a word represented by a logogram): et, at	Logogramm
	Ligature	Ligatur
	Oldstyle figures, medieval figures	Mediävalziffern

Sources

ITC publication u&lc (upper and lowercase) around 1990.

Further links