Until recently, most commercial printing involved producing film separations from which printing plates were created, and this meant the designer would require the services of a prepress bureau or a printer’s own reprographic department. Today, an increasing number of documents are sent to press digitally: platemaking equipment for offset litho printing works directly from the designer’s files, or the job is output on plates required. This is not to say that bureaux are a thing of the past. Although desktop scanners have greatly improved, only high-end bureau equipment will guarantee professional image reproduction from materials such as 35 mm transparencies. A bureau can also be invaluable in managing the conversion of files to Acrobat PDF format (see page 70), although printers are increasingly likely to offer help with this.