DryOffset best sequence practice

Discussion in 'Letterpress' started by Marizmendi, Aug 25, 2020.

  1. Marizmendi

    Marizmendi New Member

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    Hi, I work on a Dryoffset company, using Vandame 6 color machines, printing plastic cups, and for routine practice, we use the sequence rule: light colors first, dark colors last.

    However I was wondering if when you have let's say 100%Cyan + 30% Magenta, the sequence will be better if you put the magenta plate first on the cylinder, then the Cyan plate, cause this way when the inks are transferred on to the plastic cup, the magenta dots will be on top in the printed cup.
    see attached image, in which I tried to simulate the situation.
    I hope somebody has expert knowledge in this kind of workflow to help me
    thanks in advance
     

    Attached Files:

  2. mantman

    mantman Senior Member

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    I think you should ask yourself or ink supplier how much opacity your inks have. I mean offset inks have high transparency or you could try it through prepress technique of making magenta dots knock out cyan -make a hole- and apply trap -expansion- on dots or choke on cyan to magenta.
     
  3. Marizmendi

    Marizmendi New Member

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    Thanks Mantman
    Sure the opacity of the ink has a lot of importance here in this situation.... I will see what you suggest however, my concern is about the sequence at the machine, it has something to do on how the dots behave on a full solid, like in my example?

    By the way, do you know any software that makes the dots knock out as you suggest?
     
  4. mantman

    mantman Senior Member

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    Your rip can do it, not sure about other software
     
  5. Marizmendi

    Marizmendi New Member

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    We use a Rip named Dynaflex, but no, it can't do that, doesn't have that feature...
    Can your rip do it? what is it
     

  6. mantman

    mantman Senior Member

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    We used Kodak Prinergy 5 but switched CtP and now we use Prinect Metadimension, but it lacks the license of trapping, so prepress use -i think- Prinect PDF Toolbox to trap