PostScript basics

PostScript is a page description language, a protocol that is used to communicate between applications (like Adobe InDesign, QuarkXPress or MS Word) and output devices, like laser printers or platesetters, that are equipped with a PostScript interpreter. PostScript can also be used to exchange data between applications themselves and it forms the basis of the PDF file format.

Several pages on this site go into more detail about PostScript:

If you are a programmer or want to delve a little deeper, you will also find an interesting introduction to PostScript on this site.

9 August 2013

11 responses to “PostScript basics”

  1. Kirti Ahuja says:

    Which version of the Postscript is currently available in PDFs.

  2. Shawn says:

    Mr. Laurens, please, could you tell me how to import a image’s file (.jpg , .eps , ps etc) to a new ps file.

  3. Alex says:

    Thank you!

    Now I can do some relations:
    Postscrip level 3, for exemple, it is a progression in the language and PostScript level 3 RIPs mean that RIP can interpret this level of language. The way it make this interpretation, I think it is: or by CPSI (I suppose that it is a cheaper OEM tecnology, than APPE) or by APPE. I worked with Prinergy and saw Normalizer process occur in front of me all the time.
    After a little research (certainly not something new for the Sr., or as we say here in Brazil: teaching the priest to pray!), CPSI v3015 had some problem with transparency, solved with flattened PDF 1.3, nowadays v3019 without thoses issues.

  4. Alex says:

    Mr. Laurens, please,could you explain the relation between PostScript 3, CPSI and APPE. I´ve read your texts, but I could not do a clear relation between them.

    Thank you!

    • Laurens says:

      OK, let’s start with the basics:

      • PostScript is a page description language. A PostScript file defines what a page or document looks like.
      • CPSI and APPE are software libraries that Adobe sells to vendors so these can build a RIP (or renderer as it is sometimes called). Such a RIP takes a page description and uses it to output the document, usually on physical media such as paper, film or printing plates.

      Let me use an analogy: A PostScript file is to an MP3 file as a RIP is to a music application on your computer or the software of your MP3 player.

      How do CPSI and APPE relate to PostScript:

      • CPSI is the precursor of APPE. It is a PostScript interpreter: you can send a PostScript file to a RIP based on CPSI and it will make sure you get a nice print-out, or a good set of films or plates.
      • APPE was created when Adobe had already phased out PostScript. APPE cannot process PostScript files directly, it expects to be fed PDF files. A lot (or maybe all) of the vendors that build RIPs based on APPE still see the need for supporting PostScript so they typically add a PostScript to PDF convertor (Distiller or Normalizer) to their RIP or workflow. That means you can still send PostScript files to such a system. In the background they will be converted to PDF and then forwarded to the APPE component.

      Hope this clears things up a bit.

  5. Chai says:


    Thanks for your excellent article.

    one question. You wrote: “PostScript can also be used to exchange data between applications themselves and it forms the basis of the PDF file format.” I am not clear about it. Could you clarify? Or can I understand in this way:if I export a PDF from indesign, and I use different PDF viewer to read it, such as Preview, Acrobat or VPS, I may get different display result because they have different RIP built in?

    So eager to hear from you answer. Thanks

    • Laurens says:

      That latter statement unfortunately is true – depending on the viewer application you use a PDF may be displayed differently.

  6. Emanuele says:

    PostScript could be a real madness but using your guide I reached my goals. Thank you for the help =) Keep this up. It was like a salvation!

  7. Laurens says:

    You can convert .jpg files to .eps using applications like Photoshop or other image editing applications.

  8. gloria guzman says:

    I have an .jpg file I need to concert it to a .eps file is this possible and if so how?

  9. Steven Teosin says:

    The site is precisely informative and easily browsable. Thank you and keep it up.