Section 78. About PostScript

78. About PostScript

Before You Begin

77 About Acrobat Distiller

See Also

80 Create Custom Settings

Distiller converts documents to the PDF file format, but it can convert only one type of document: PostScript files (including Encapsulated PostScript [EPS] files). It is strictly a PostScript-to-PDF conversion program. Many page-layout and illustration programs allow you to save a file in the PostScript format, but for most users, this is unnecessary. They can simply print directly to the Adobe PDF printer driver, which converts a document into PostScript format and sends it directly to Distiller for conversion into a PDF document.

KEY TERMS

PostScript A page description language that enables printers to output text and images exactly as they appear onscreen.

Page description language A software language that describes the text and images on a page mathematically for precise reproduction on a printer or other output device.

So, what is PostScript ? It is a software language, but rather than being a language that tells computers what to do, such as Visual Basic or C++, it tells printers how to print documents. Specifically, PostScript is a page description language . With PostScript, every letter, line, and image in your document is precisely and mathematically defined. Any printer that understands PostScript can then reproduce that document. PostScript was invented by Adobe Systems around the same time that the PageMaker page layout application and the Apple LaserWriter were introduced, and together the three of them created the desktop publishing revolution.

PDF is also a page description language, but it is a much more efficient one. It produces smaller files and prints faster than raw PostScript. (PDF files still send PostScript information to the printer, but because the data in a PDF document is better organized, the final output to a printer tends to be faster.) For this reason, most commercial printers prefer working with PDF files. Because PDF also offers the advantages of easy viewing on virtually any operating system and in any Web browser, it's easy to understand why PDF is enjoying ever-growing popularity.

Most popular illustration or page layout applications can output files in the PostScript format because that has traditionally been the format for high-end, commercial printing. Many (including Adobe InDesign and Adobe Illustrator) can create PDF output directly, either by saving as PDF or with an Export to PDF command. And, of course, all applications can create PDF output by simply printing to the Adobe PDF virtual printer.

Where Distiller comes in is in its capability to convert PostScript and Encapsulated PostScript (EPS) files to PDF quickly and easily while offering a high level of control over the process. The three ways to convert PostScript files to PDF with Distiller are

• Open the file with Distiller The Open command in the File menu lets you locate and open a specific PostScript or EPS file. The file is automatically converted to PDF as soon as it is opened.

• Drag the file into the Distiller window Simply dragging one or more file icons from a desktop folder into the Distiller window converts them all to PDF.

• Set up a watched folder Use the Watched Folders command in the Distiller Settings menu to set up one or more watched folders. While Distiller is running, any PostScript or EPS files placed in these folders are automatically converted to PDF.

All three of these methods work only with PostScript or EPS files. To convert other file types to PDF, you have to work from within the source application, either by saving/exporting to PDF or by printing to the Adobe PDF virtual printer.