Dot sharpness / 3 quarter hafttone fills in / High dotgain

Discussion in 'Heidelberg Printing Presses' started by deltaE, Feb 9, 2018.

  1. deltaE

    deltaE New Member

    Joined:
    Feb 2018
    Messages:
    2
    Location:
    Vietnam
    Hi All,

    This job was printed on a 250 gsm coated paper, CD102, CtP Plate. And I got this issue.
    In the picture, these are 80% and 40% area. What do you think about this problem?

    Thanks & regards,
    DeltaE
     

    Attached Files:

  2. Abhi

    Abhi Member

    Joined:
    Mar 2017
    Messages:
    84
    Location:
    Nepal
    Can be the ink.
    Is the problem occuring with other ink in the same unit?
    Can be the blankets and packings.
    Make sure the blankets and packing are upto spec.
    Can be the dampening.
    Check your dampening solution chemistry.

    But before fiddling with the press, make sure you have the plates done right. Every press has a different dot gain curve for different types of paper stock.
    You may need to get the plates done right from the prepress.
     
  3. Bill Borcicky

    Bill Borcicky Senior Member

    Joined:
    Jul 2012
    Messages:
    211
    Location:
    U.S. Amory, Ms.
    If you look at the plate with an eyeglass you can see the dots. if the dot pattern is crisp and clear , the problem is pressure . if it is the same as your picture , it would be the plate .
     

  4. deltaE

    deltaE New Member

    Joined:
    Feb 2018
    Messages:
    2
    Location:
    Vietnam
    Dear Alls,

    I am sorry for my delay. The dot in the plate looks good.
    In my opinion, it seems to be the bad combination between ink and fount solution, although pH of dampening solution always is kept at 5.2.
    In the coming time, I will try another fount solution and do hope it would have some better effect on this issue.

    Regards,
    DeltaE
     
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