Cast iron of characters

A cast iron of characters , in Typography, is a whole of Glyphe S, i.e. of visual representations of character S, of the same family, of the same style, body and grease. It is distinguished from the Police from writing or police force (term more used in the word processing) which gathers all the bodies and greases of the same family, whose style is coordinated, in order to form a Alphabet, or the overall of characters of language, complete and coherent representation. Although the two terms are frequently confused, they are thus not equivalent.

This term comes owing to the fact that the first pig iron and cast iron of characters was made of an alloy of Plomb and from molten Antimoine in order to reproduce several identical characters starting from a single mould.

Today, one also speaks about cast iron for the whole of natures used in Informatique, for a purely data-processing application (Internet, presentation, etc) or an application in Imprimerie.

The police forces in data processing

In data processing, there were several pig iron and cast iron formats; the Bitmap S (at size fixes), and two types of vectorial them: the police forces type Hershey , which one was satisfied to put on the scale without specific particular correction to their size and the more recent police forces at correction of scale. Both could be increased, directed or stretched without loss of quality, but the “quality” of Hershey rather made them hold for the graph plotters and postings coarse on screen.

Police forces of printers

During years, PC softwares could exploit a font face only if this one were coded in the printer. Moreover, each police force was defined only in some quite precise faces or body. For example, one had of “Mail 10 and 12” and “Times 8,9 10,11,12,18”.

With this system, each letter of each police force in each face was represented by a more or less important whole of points according to the resolution of the printer.

Vectorial police forces

The vectorial police forces with correction of scale comprise several different encodings:

The PostScript police forces

With the adoption of the language PostScript like normalizes impression, the use of the font faces could evolve/move, because the models of printers which had PostScript technology could be freed from the limitation of the size.

There exist two types of PostScript police force: those of Standard 1 and those of Standard 3.

The PostScript police forces called Type 1 are coded by vectors (Courbe of Bézier) describing the shape of each letter rather than by points. The printer is given the responsability to recompute the points at the time of the exit according to its resolution; thus one can “rastériser” (" flasher") a document designed for a laser writer in: 1200 PPP.

Police forces known as of Standard 3, allowing assemblies of characters, and the pig iron and cast iron SVG, allowing the assemblies of characters as well as the transparency and the filling by reasons or color gradations, is most advanced. They are little or not used in professional impression because they pose problems in flows of PostScript production and pdf.

The PostScript police forces take again the drawings of the professional typographers and are thus preferred in graphic arts.

The TrueType police forces

The police forces TrueType of Microsoft, also declined in OpenType by Apple, are equivalent to the Type 1 near of Adobe to an exception: their management is entirely integrated into Microsoft Windows (starting from versions 3.0 and 3.1) thanks to a specialized program called Standard Adobe Manager (ATM). At the beginning they used named curves " splines" and were impossible to print in professional impression; however Type 42 made possible this impression. This format is created by PostScript or Distiller (Adobe).

They were an extraordinary success, mainly related to the success of Microsoft Windows itself. A long time they were not employed much on the Apple Macintosh because, Mac being especially used for graphic arts, those did not use this kind of police forces, which could not at the time being gérées by RIP (raster image processor).

Legal aspects in the anglophone countries

The American regulations do not make it possible to protect by copyright the design from the typefaces , whereas it allows the patent filling of an innovative design.

The numerical police forces having a particular design become often copyrightables as a computer software. The names of the font faces can become registered trademarks. The consequence of these protection legal is that certain police forces exist under multiple names, and different implementations.

Certain elements of software engines used to post the police forces on computers are associated with software patents. In particular, Apple deposited a patent on some of the algorithms of hinting for TrueType, obliging the alternate open-source such as FreeType to use different algorithms.

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