Most page layouts, supplied either as a ‘native’ QuarkXPress or InDesign file or as a PDF, are output to an imagesetter though a raster image processor or RIP (pronounced ‘rip’). This device – usually a PC or Mac running specialized software – changes the outlines of the type and drawings from PostScript, the vector-based programming language used by computers to describe pagr ;ayout, into a bitmap (an array of dots) that can be printed by a filmsetter or digital press. Part of the RIP’s job is to manage the creation of the ‘halftone’ patterns into which images and tints are broken up for printing. Although the DTP files may contain instructions to the RIP, the printer’s RIP may not understand all of them or may be set, for very good reasons, to ignore them. ‘Late binding’ is a term used to describe last-minute changes made within PostScript files while they are in the RIP, such as adding trapping and imposition information.