不親切な用語解説--「font」その8

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• A font, from Middle French fonte, meaning "(something that has been) melt(ed) [akin to Fondue]" and referring to letters of a typeface produced by casting molten metal at a type foundry, consists of a set of glyphs (images) representing the characters from a particular character set in a particular typeface. Historically, fonts came in specific sizes determining the size of characters, and in quantities of sorts or number of each letter provided. The design of characters in a font took into account all these factors. As the range of typface designs increased and requirements of publishers broadened over the centuries, fonts of specific weight (blackness or lightness) and stylistic variants―most commonly regular or roman as distinct to italic, as well as condensed) have led to font families, collections of closely-related typeface designs that can include hundreds of styles. A font family is typically a group of related fonts which vary only in weight, orientation, width, etc, but not design. For example, Times is a font family, whereas Times Roman, Times Italic and Times Bold are individual fonts making up the Times family. Font families typically contain several fonts, though some, such as Helvetica, may consist of dozens of fonts. Helvetica, Century Schoolbook, and Courier are examples of three widely distributed typefaces.
  English-speaking printers have used the term fount for centuries to refer to the multi-part metal type used to assemble and print in a particular size and typeface. Type foundries have cast fonts in lead alloys from the 1450's until the present, although wood served as the material for some large fonts called wood type during the 19th century, particularly in the United States of America. In the 1890's mechanization typesetting allowed automated casting of fonts on-the-fly as lines of type in the size and length needed. This was known as continuous casting, and remained profitable and widespread until its demise in the 1970's. The first machine of this type was the Linotype invented by Ottmar Mergenthaler.
  During a brief transitional period (circa 1950's – 1990's), photographic technology, known as phototypesetting, produced fonts which came on rolls or discs of film. Photographic typesetting permitted optical scaling, allowing designers to produce multiple sizes from a single font, although physical constraints on the reproduction system used still required design-changes at different sizes―for example, ink traps and spikes to allow for spread of ink encountered in the printing stage. Manually-operated photo-composition systems using fonts on rolls of film allowed fine kerning between letters without the physical effort of manual typesetting, and spawned an enlarged type-design industry in the 1960's and 1970's.
  The mid-1970's saw all of the major typeface technologies and all their fonts in use: letterpress, continuous casting machines, phototypositors, computer-controlled phototypesetters, and the earliest digital typesetters―hulking machines with tiny processors and CRT outputs. From the mid-1980's, as digital typography has grown, users have almost universally adopted the American spelling font, which nowadays nearly always means a computer file containing scalable outline letterforms ("digital font"), in one of several common formats. Some fonts, such as Verdana, are designed primarily for use on computer screens.
  Digital fonts store the image of each character either as a bitmap in a bitmap font, or by mathematical description of lines and curves in an outline font, also called a vector font. When an outline font is used a rasterizing routine in the application software renders the character outlines, interpreting the vector instructions to decide which pixels should be black and which ones white. Rasterization is straightforward at high resolutions such as those used by laser printers and in high-end publishing systems. For computer screens, where each individual pixel can mean the difference between legible and illegible characters, some digital fonts use hinting algorithms to make readable bitmaps at small sizes.
  Digital fonts also contain data representing the metrics used for composition, including kerning pairs, component-creation data for accented characters, glyph-substitution rules for Arabic typography and for connecting script faces, and for simple everyday ligatures like fl. Common description languages that format digital type include METAFONT, PostScript, TrueType and OpenType. Applications using these font formats, including the rasterizers, appear in Microsoft and Apple Computer operating systems, Adobe Systems products and those of several other companies.

Typeface - Wikipedia, the free encyclopedia の中の『History of the term font』より

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