See the following definitions:
What is PostScript?
The PostScript language is an interpretive programming language with powerful graphics capabilities. A program in this language communicates a description of a document to an output device (such as a printer). The description may be device-independent. The page description and interactive graphics capabilities of the PostScript language include the following features:
- Arbitrary shapes made of straight lines, arcs, rectangles, and cubic curves. Such shapes may self-intersect and have disconnected sections and holes.
- Painting operators that permit a shape to be outlined with lines of any thickness, filled with any color, or used as a clipping path to crop any other graphic. Colors can be specified as gray-level (pseudo-grayscale), RGB, CMYK. Repeating patterns, color mapping and color separations are also other features of the PostScript language.
- Text is fully integrated with graphics. In the PostScript language’s graphics model, text characters (both user defined and standard) are treated as graphical shapes that may be operated on by any of the normal graphics operators.
- The PostScript language can describe images sampled at any resolution and a variety of color models. Thus, it provides a number of different ways to reproduce images on an output device.
- A general coordinate system that supports all combinations of linear transformations, including translation, scaling, rotation, reflection, and skewing. These transformations apply uniformly to all elements of a page, including text, graphical shapes, and images.
- A PostScript language page description (or program) can be rendered on a printer by presenting it to a PostScript interpreter controlling the printer. As the interpreter executes commands to paint characters, graphical shapes, and sampled images, it converts the high-level PostScript language description into the low-level raster data format for that printer.
|| Much of the preceding information came from the Adobe PostScript Language Reference Manual -Second Edition.
When would you need to use PostScript?
Generally, you would need to use PostScript in the following scenarios:
- To match font styles with other users in the organization
- To work with Macintosh computers
- The work requires the rendering of graphic images in a particular way which possibly only PostScript can provide
- To be compatible with a particular application or environment (this is more common in certain UNIX (R) environments)
Are there any potential disadvantages in using PostScript?
Some of the disadvantages related to PostScript printing are:
- Can be slower at printing -- Simple graphics or mixed text and graphics jobs printed in PostScript may take up to 2 to 5 times longer to print than the same job sent as PCL.
- Memory intensive -- PostScript generally needs more printer memory to produce a job. There is no direct correlation between file size and the amount of memory needed to produce a job.
Are there any potential advantages in using PostScript?
Refer to the section entitled "When would you need to use PostScript?"
Also, for some complex graphics jobs, PostScript MAY be faster.
What is PCL?
Hewlett-Packard created the PCL (Printer Control Language) printer language to provide an efficient way for application programs to control a wide range of printer features across a number of different printing devices. PCL commands are compact escape sequence codes that are embedded in the print job data stream. HP PCL formatters and fonts are designed to quickly translate application output into high-quality, device-specific, raster print images. PCL has evolved through five major levels of functionality driven by the combination of printer technology developments, changing user needs and application software improvements. The five phases of the PCL printer language are:
|PCL 1 - Print and Space
||Basic printing single user workstation output functionality
|PCL 2 - EDP/Transaction
||General, multi-user printing
|PCL 3 - Office Word Processing
||Office document production
|PCL 4 - Page formatting
||Page printing functionality
|PCL 5 - Office Publishing
||Font scaling and HPGL/2 added
The PCL printer language model succeeds because:
- All HP LaserJet printers implement PCL printer language features consistently.
- HP printers have the ability to ignore most unsupported commands.
|| Much of the preceding information came from the PCL 5 Printer Language Technical Reference Manual - 10/92.
Are there any potential advantages in using PCL instead of PostScript?
Faster print speed -- PCL, in most instances, will print faster (up to 2 to 5 times) than PostScript, especially with simple text and graphics.
Generally less Memory intensive than PostScript -- PostScript may need more printer memory to produce a job. There is no direct correlation between file size and the amount of memory needed to produce a job. Using PCL there is a better correlation between printer memory and file size. Using this information you can estimate if you are going to need more memory depending on the document file size.
Are there any potential disadvantages in using PCL instead of PostScript?
Some graphics may not print as well as a PCL image as they do as a PostScript image.
Some customers may see a difference with a particular file while others cannot and some applications may print better in PCL or vice-versa. Many of these differences can be resolved through driver or application settings.
Some users want to have PostScript type faces available in PCL mode. The way to accomplish this is to purchase a third party program to convert PostScript fonts into a format compatible with PCL. Such programs are available from Adobe (R) (Adobe Type Manager) or Bitstream (Bitstream Facelift) for example.