The PostScript language

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP.

PostScript is a page-description language defined by the Adobe Corporation which, since its introduction in 1985, has become the industry standard. Almost all page-layout programs and graphics programs now output PostScript-language code. (Many business and scientific application programs also have this ability.) The language is defined in the “Red Book”, namely the PostScript Language Reference Manual (3rd edition) (Adobe, 1999).

When it comes to taking a PostScript-language program and generating output on a physical machine, many things have to be resolved. The language itself is potentially device independent; the program does not have to specify the output resolution, medium, or (for instance) paper tray to use. Typically, some of these factors are specified in the interests of efficiency or image quality—for example, using PostScript printer description (PPD) files. In the absence of such specifications, it is up to the interpreter to decide which physical direction is "up", how color images are to be printed (for example, perhaps four monochrome separations are required, or perhaps the interpreter is driving a color device). The behavior required may vary from one job to another: we might not care which way round an image is printed, but want it to use as little media as possible, for instance.