The content of this page has been moved to the main PostScript page.

30 December 2016

5 responses to “Basics”

  1. 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.

  2. 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.

  3. 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.