Font
In metal typesetting, a font is a particular [|size, weight, and style] of a typeface, defined as the set of fonts that share an overall design.
For instance, the typeface Bauer Bodoni includes fonts "Roman", "" and ""; each of these exists in a variety of sizes. In traditional printing, fonts were physically created using metal or wood type, with a font for each size.
In the digital description of fonts, the terms font and typeface are often used interchangeably. For example, when used in computers, each style is stored in a separate digital font file. Most are scalable fonts, so all sizes of a style are encompassed in one font.
In both traditional typesetting and digital design, the term font refers to a specific style or version of a typeface.
Image:Sorts on composing stick.jpg|thumb|right|Metal type sorts arranged on a composing stick
Spelling and etymology
The word font or fount derives from Middle French fonte, meaning "cast iron". The term refers to the process of casting metal type at a type foundry.The spelling font, originally used only in the United States, is now the accepted one. Fount, historically used in the UK and Commonwealth countries, is considered archaic.
Metal type
In a manual printing house the word "font" would refer to a complete set of metal type that would be used to typeset an entire page. Upper- and lowercase letters get their names because of which case the metal type was located in for manual typesetting: the more distant upper case or the closer lower case. The same distinction is also referred to with the terms majuscule and minuscule.Unlike a digital typeface, a metal font would not include a single definition of each character, but commonly used characters would have more physical type-pieces included. A font when bought new would often be sold as 12pt 14A 34a, meaning that it would be a size 12-point font containing 14 uppercase "A"s, and 34 lowercase "a".
The rest of the characters would be provided in quantities appropriate for the distribution of letters in that language. Some metal type characters required in typesetting, such as dashes, spaces and line-height spacers, were not part of a specific font, but were generic pieces that could be used with any font. Line spacing is still often called "leading", because the strips used for line spacing were made of lead. This spacing strip was made from lead because lead was a softer metal than the traditional forged metal type pieces and would compress more easily when "locked up" in the printing "chase".
In the 1880s–1890s, "hot lead" typesetting was invented, in which type was cast as it was set, either piece by piece or in entire lines of type at one time.
Characteristics
In addition to character height, when using the mechanical sense of the term, there are several other characteristics which may distinguish fonts, though they would also depend on the script that the typeface supports. In European alphabetic scripts, i.e. Latin, Cyrillic, and Greek, the main such properties are the [|stroke width, called weight], the [|style or angle], and the [|character width].The regular or standard font is sometimes 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. Roman can also refer to the language coverage of a font, acting as a shorthand for "Western European".
Different font styles within the same typeface can be used in a single design to enhance readability and emphasis, or in a specific design to make it be of more visual interest.
Weight
The weight of a particular font is the thickness of the character outlines relative to their height.A typeface may come in fonts of many weights, from ultra-light to extra-bold or black; four to six weights are not unusual, and a few typefaces have as many as a dozen. Many typefaces for office, web and non-professional use come with a normal and a bold weight which are linked together. If no bold weight is provided, many renderers support a bolder font by rendering the outline a second time at an offset, or smearing it slightly at a diagonal angle.
The base weight differs among typefaces; that means one font may appear bolder than another font. For example, fonts intended to be used in posters are often bold by default while fonts for long runs of text are rather light. Weight designations in font names may differ in regard to the actual absolute stroke weight or density of glyphs in the font.
Attempts to systematize a range of weights led to a numerical classification first used in 1957 by Adrian Frutiger with the Univers typeface: 35 Extra Light, 45 Light, 55 Medium or Regular, 65 Bold, 75 Extra Bold, 85 Extra Bold, 95 Ultra Bold or Black.
Deviants of these were the "6 series", e.g. 46 Light Italics etc., the "7 series", e.g. 57 Medium Condensed etc., and the "8 series", e.g. 68 Bold Condensed Italics.
From this brief numerical system it is easier to determine exactly what a font's characteristics are, for instance "Helvetica 67" translates to "Helvetica Bold Condensed".
File:Regular and bold.png|thumb|Bold and regular versions of three common fonts.
Helvetica has a monoline design and all strokes increase in weight in bold.
Less monoline fonts like Optima and Utopia increase the weight of the thicker strokes more.
In all three designs, the curve on 'n' thins as it joins the left-hand vertical.
The first algorithmic description of fonts was made by Donald Knuth in his 1986 Metafont description language and interpreter.
The TrueType font format introduced a scale from 100 through 900, which is also used in CSS and OpenType, where 400 is regular.
The Mozilla Developer Network provides the following rough mapping to typical font weight names:
| Names | Numerical values |
| Thin / Hairline | 100 |
| Ultra-light / Extra-light | 200 |
| Light | 300 |
| Normal / regular | 400 |
| Medium | 500 |
| Semi-bold / Demi-bold | 600 |
| Bold | 700 |
| Extra-bold / Ultra-bold | 800 |
| Heavy / Black | 900 |
| Extra-black / Ultra-black | 950 |
Font mapping varies by font designer. A good example is Bigelow and Holmes's Go Go font family. In this family, the "fonts have CSS numerical weights of 400, 500, and 600. Although CSS specifies 'Bold' as a 700 weight and 600 as Semibold or Demibold, the Go numerical weights match the actual progression of the ratios of stem thicknesses: Normal:Medium = 400:500; Normal:Bold = 400:600".
The terms normal, regular and plain are used for the standard-weight font of a typeface. Where both appear and differ, book is often lighter than regular, but in some typefaces it is bolder.
Before the arrival of computers, each weight had to be drawn manually. As a result, many older multi-weight families such as Gill Sans and Monotype Grotesque have considerable differences in weights from light to extra-bold. Since the 1980s, it has become common to use automation to construct a range of weights as points along a trend, multiple master or other parameterized font design. This means that many modern digital fonts such as Myriad and TheSans are offered in a large range of weights which offer a smooth and continuous transition from one weight to the next, although some digital fonts are created with extensive manual corrections.
As digital font design allows more variants to be created faster, a common development in professional font design is the use of "grades": slightly different weights intended for different types of paper and ink, or printing in a different region with different ambient temperature and humidity. For example, a thin design printed on book paper and a thicker design printed on high-gloss magazine paper may come out looking identical, since in the former case the ink will soak and spread out more. Grades are offered with characters having the same width on all grades, so that a change of printing materials does not affect copy-fit. Grades are common on serif fonts with their finer details.
Fonts in which the bold and non-bold letters have the same width are "duplexed".
Style
Slope
In European typefaces, especially Roman ones, a slope or slanted style is used to emphasize important words. This is called italic type or oblique type. These designs normally slant to the right in left-to-right scripts. Oblique styles are often called italic, but differ from "true italic" styles.Italic styles are more flowing than the normal typeface, approaching a more handwritten, cursive style, possibly using ligatures more commonly or gaining swashes.
Although rarely encountered, a typographic face may be accompanied by a matching calligraphic face, giving an exaggeratedly italic style.
In many sans-serif and some serif typefaces, especially in those with strokes of even thickness, the characters of the italic fonts are only slanted, which is often done algorithmically, without otherwise changing their appearance. Such oblique fonts are not true italics, because lowercase letter shapes do not change, but they are often marketed as such. Fonts normally do not include both oblique and italic styles: the designer chooses to supply one or the other.
Since italic styles clearly look different than regular styles, it is possible to have "upright italic" designs that take a more cursive form but remain upright; Computer Modern is an example of a font that offers this style. In Latin-script countries, upright italics are rare but are sometimes used in mathematics or in complex documents where a section of text already in italics needs a "double italic" style to add emphasis to it. 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 styles is also a matter of local preference.