Cocoa & Spot Colors

Discussion in 'Mac Programming' started by superscape, Nov 10, 2014.

  1. superscape macrumors 6502a

    superscape

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    #1
    Hi,

    I've been looking into creating spot colours (e.g. Pantone 032 etc) in Cocoa. I don't see any way of doing it in CoreGraphics, unless I'm being dumb and missing something?

    Does anyone know how this is generally done? Just a rough point in the right direction would be appreciated!

    Thanks
     
  2. numero macrumors regular

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    #2
    I started writing a reply, but then I realized I don't really understand your question. I know what you mean by Pantone colors. Could you explain your need a little further? Are you wanting to display on screen a proximity of the Pantone color? Do you want to write the color values to a file? Or something else? The answers would help shape my response.
     
  3. superscape, Nov 24, 2014
    Last edited: Nov 24, 2014

    superscape thread starter macrumors 6502a

    superscape

    Joined:
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    #3
    Hi there,

    Thanks for getting back to me!

    What I want to do is create a PDF that contains an additional separation. That's to say, a additional spot colour. I've attached a PDF as an example which has a spot colour I've made up called "My Spot Color' (the name and RGB values could be arbitrary or from a library such as Pantone).

    If you look at the screenshot from Adobe Acrobat's Output Preview tool, you can see how the spot colour appears.

    If I was to print this PDF out as separations (as you would for a printing press) then I'd get 4 separations for the CMYK red colour and a single separation for the green.

    Hope that makes sense!

    Thanks for you help
     

    Attached Files:

  4. numero macrumors regular

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    #4
    I kind of thought that is where you were going. Unfortunately, my experience is in the opposite direction. I had a previous project where I had to take files that represented the separations (single bit TIFF files) and save them out as a composite color image. C, M, Y and K as well as spot colors.

    This problem intrigues me. I may keep working on this in the background -- just to find out how the representation is made in the PDF.

    Sorry I couldn't contribute anything on this one.

    -numero
     
  5. superscape thread starter macrumors 6502a

    superscape

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    #5
    No problem. Thanks for your time.

    It looks like it's possible using PDFLib* but it costs a small fortune.

    At the moment, I'm creating PDFs with spot colors by sending info to a PHP based web service of my own devising which uses TCPDF to generate the PDF I need and send me the PDF back.

    Whilst that works, its a scruffy solution and relies on network connectivity. I'd like my app to be self contained and make the PDFs itself. I can do everything I need in Core Graphics *except* the spot colors. How infuriating!

    I guess another solution might be to create my graphics as postscript then convert that to PDF. Again, that seems scruffy although at least it doesn't need a network connection.

    Hmmm... still interested in any ideas or suggestions!






    * http://www.pdflib.com/products/pdflib-family/pdflib/
    ** http://www.tcpdf.org
     
  6. superscape thread starter macrumors 6502a

    superscape

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    #6
  7. superscape thread starter macrumors 6502a

    superscape

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    #7
    Just wondered whether you ever got chance to take a look at this? I stuck with my TCPDF solution in the end but I'd love to be able to support spot colors in my app.
     
  8. numero macrumors regular

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    #8
    I just saw this. A year and a day isn't too long to wait for a reply. :)
    I do not have a better answer than what you came up with.

    -numero
     
  9. superscape, Sep 25, 2016
    Last edited: Oct 27, 2016

    superscape thread starter macrumors 6502a

    superscape

    Joined:
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    #9
    Hah hah! Thanks for the response, albeit after a length break.

    We ended up using TCPDF for a lot of stuff, and a home-grown Obj-C based PDF creation library for the simple stuff. It does seem like a major omission for Core Graphics though. I do wish Apple would add spot colour support.
     

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