It has become the printing and imaging technology of choice for corporations, publishers and government agencies throughout the world. 75 % of all commercial publications are printed on Adobe PostScript devices. These include
• black/white printers,
• colour printers,
• image setters,
• latesetters and
• direct digital printing systems.
By the way, Postscript is not limited to be used in printers or other devices used in the professional printing process. Also computer screens have been driven by Postscript.
The Postscripts language has had two major upgrades. The first version, known as PostScript Level 1, was introduced in 1984. Post script 1 was implemented by the Apple on the Apple LaserWriter printer. Postscript supported many new features at that time like outline fonts and vector graphics so it became popular among graphic printers. The structure of the Postscripts language, which is similar to a conventional computer programming language, meant that these advanced features could be used in a very versatile and creative manner to create complex images and designs. Apple continued to upgrade this language and introduced the Apple LaserWriter Plus. The new printer had more memory and many more outline fonts.
Nowadays, Postscript has become an industry standard for the typesetting of books, magazines and other complex publications.
PostScript Level 2
PostScript Level 2 was introduced in 1991, and included several improvements: improved speed and reliability, support for in-RIP separations, image decompression (for example, JPEG images could be rendered by a Postscripts program), support for composite fonts, and the form mechanism for caching reusable content.
The disadvantage of Postscripts was its speed. Postscript Level 1 required an enormous amount of processing power, and was often very slow. The capabilities of the various releases were also confusing, as the language was enhanced as each new printer was equipped with PostScript, extensions to PostScript were created to cope with colour, patterns, printers with multiple paper trays, duplex etc. PostScript Level 2 incorporates all the enhancements made to the original PostScript, setting a new baseline for the language. PostScript Level 2 is entirely backwards compatible with the original PostScript, and will produce the same image for a job as a PostScript Level 1 printer.
PostScript Level 3
Postscript level 3 was introduced in 1997, supports more fonts, better graphics handling, and includes several features to speed up PostScript printing.
PostScript 3 (Adobe dropped the "level" terminology in favor of simple versioning) came at the end of 1997, and along with many new dictionary-based versions of older operators, introduced better color handling, and new filters (which allow in-program compression/decompression, program chunking, and advanced error-handling).
The new graphics capabilities include
• smooth shading,
• idiom recognition,
• masked images,
• finer colour controls,
• superscreens, and
• fast image.
Other improvements of PostScript Level 3 include
• In–RIP Trapping,
• direct PDF printing, and
• DeviceN.
In–RIP Trapping is a new capability of the PostScript 3 interpreter that executes trapping commands at the raster image processor (RIP), automating complex and time consuming prepress tasks. Trapping is specified, then rendered at print time rather than as a separate production step prior to RIPping. Direct PDF printing is an optional capability of the Adobe PostScript 3 interpreter that improves workflow productivity by allowing the RIP to accept and print files in the Portable Document format (PDF) without
printing through an application – the PDF files don’t have to be opened with an application and then be printed from that application but can be sent directly to the RIP.
DeviceN is a new Level 3 operator that handles any number of colours, from duotones and tritones, to Haxachrome™ and beyond, in a composite workflow. This feature is supported by Adobe Photoshop 5.0. It makes prepress applications easier to use and
more efficient, representing all colour on one single page, instead of using one page per colour.
Benefits of Adobe Postscript are :
Quality. Adobe Postscript was designed from the outset to work seamlessly with every major operating system and color management system and prints anything, from everyday business correspondence to complex colorful brochures. The printed version always looks exactly as it does on-screen without reformatted pages or misplaced artwork.
Network. With support on every major computer platform Adobe Postscript devices are ideal for networks large and small.
- PostScript became commercially successful due to the introduction of the graphical user interface, allowing designers to directly lay out pages for eventual output on laser printers. However, the GUI's own graphics systems were generally much less sophisticated than PostScript; Apple's QuickDraw, for instance, supported only basic lines and arcs, not the complex B-splines and advanced region filling options of PostScript. In order to take full advantage of PostScript printing, applications on the computers had to re-implement those features using the host platform's own graphics system. This led to numerous issues where the on-screen layout would not exactly match the printed output, due to differences in the implementation of these features.
Print documents regardless of printing device computer platform or operating system. This is device independence. Adobe Postscript language file is independent of the device that created it and the device that prints it.
Print documents not created by the user including documents sent by email imported from new media such as CD-ROM or downloaded from the Internet.
Select the best device for users' needs from a wide variety of Adobe Postscript devices currently available.
Print easily across networks large or small which incorporate a variety of computers operating systems, applications and printing systems anywhere in the world.
Adobe Postscript printers and systems work independently of any network configurations ensuring seamless operation in any environment.
Print in color with the assurance that regardless of device the colors in the output will be what the user intended.
Performance. Adobe continuously optimizes the Adobe Postscript system to enhance performance. The flexibility of Adobe Postscript offers manufacturers the freedom to optimize the printing environment with technologies such as memory reduction compression and coprocessors.
Compatibility. Whether using Microsoft Windows Apple Macintosh, UNIX, OS/2, DOS, or a networked combination, Adobe Postscript delivers consistent high-quality results.
- Typically, PostScript programs are not produced by humans, but by other programs. .