Bar marking down the sheet

Discussion in '4-Color Offset Presses +' started by jrussuk, Dec 7, 2013.

  1. jrussuk

    jrussuk Member

    Joined:
    Feb 2012
    Messages:
    7
    Location:
    London, England
    Hi
    I always have trouble with bar marking when im printing a 4 colour solid on heavy stock.I'm Running a 5 colour pm52. All roller pressures are correct. I can set up ok on lighter stock (150gsm) but when I print the job on 350gsm the bar marking down the sheet appers. I've run a pull of each separate unit and theres no marking on any units. Anyone got any advice?
    Many Thanks
     
  2. Bill Borcicky

    Bill Borcicky Senior Member

    Joined:
    Jul 2012
    Messages:
    214
    Location:
    U.S. Amory, Ms.
    what speed are you running? often times if you slow the speed down on solids it helps. Also look at your guides, you may have to reposition them.
     
  3. jrussuk

    jrussuk Member

    Joined:
    Feb 2012
    Messages:
    7
    Location:
    London, England
    Thanks for the reply. I was running the job about 8k
     

  4. turbotom1052

    turbotom1052 Senior Member

    Joined:
    Oct 2008
    Messages:
    1,044
    Location:
    Vermont
    i recommend you start up the press and bring it up to the speed until the mark shows. Then just stop the press dead while still on impression. Go in between each unit and look at the partially printed sheet until you find the unit thats causing the mark. Once you narrow down where its happening you can begin to figure out how to eliminate the mark.
     
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