Colour Sequence Process Work

Discussion in '1-Color and 2-Color Offset Presses' started by Dot4Dot, Nov 26, 2007.

  1. Dot4Dot

    Dot4Dot New Member

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    Hi,
    Im running a SM52 Two colour press, and am mainly producing lots of process
    work, can someone advise me of the best colour sequence for this sort of work ? I normally run mag/cyan then yellow/ black. having issues with colour
    IE most blues end up purple even though the control strips are correct.
    the firm I work for do not have A Densitometer.
    And I rely on running the colours to strenght I Feel its a pre press issue but this is falling on deaf ears. Previous printers have all had the same problems.
    Any advice any one

    thanks MT
     
  2. billy

    billy Member

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    I suggest, you use a densitometer to check your density and inkzone as well as dot gain .
     
  3. NotAGooner

    NotAGooner Senior Member

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    I ran a MOZP for years and ALWAYS ran yellow K first with densitometer readings on both, that way you can run cyan and magenta by eye using the matchprint for comparison.

    This allows you to adjust in my view, the 2 main colours which affect the final print with very little compensation.
     
  4. Dot4Dot

    Dot4Dot New Member

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    Thanks guys,
    Boss is at last looking into a basic Densitometer,as for dot gain Billy your on to it, some thing is a miss and as the press is very new, the boys from the big heidelberg are looking into it. Hey not a gooner! will give that sequence a shot cheers.
     
  5. ibler

    ibler Member

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    Hey dot... there is also a possibility that ink contributes to the "discrepancy" in the color. Some inks behave a certain way when run wet on wet. the same c/m ink may produce different hues when run m/c. Try talking to your ink provider.

    Billy's suggestion is the best option for you. There is no other way to check accuracy than by using a measuring device. Once you have a densitometer, it will be easier to guess where the fault lies. When you get the first two colors right, you can then play "by eye using matchprint for comparison".
     
  6. floris

    floris Member

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    I like to run C +Y than Black + M because you don't have to wash and because you can control the image with the magenta. But then it all depends on the image you are printing. If this is for example a mostly blue bookcover you should end with cyan. But be sure to density measure the first run! Black, cyan and then magenta,yellow is also a common sequence. Experience is everything in this game!
     
  7. jetscreamer

    jetscreamer Senior Member

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    I've always run cyan-magenta and black-yellow on a two colour press using my pms book for ink denisty. By having different percentage screens in your colour bars (eg: 40% 80%) as well as solids there is no reason not to achieve a sweet print job. I have a colour bar file i designed if you would like i can email it to you.
     
  8. marker

    marker Member

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    i almost always go c&m then y&k this way i will have more setup sheets and the blue builds will register. black is usually mostly type and shadows and if yellow is out you can`t normally tell. to the human eye red and blue is easiest seen. and you should always consider power build up on the 2nd pass. do you want to be stopping all the time to clean the blue blanket. blue is easily corrupted by powder. i have run yellow for so long on the 2nd pass that powder was falling off the blanket it chunks. ( it was a long run on coated with heavy coverage)
     
  9. turbotom1052

    turbotom1052 Senior Member

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    i remember running 4/c process on both 2 color presses and even one color at a time on a single color press. my feeling is that the last to run colors should be the colors that the majority of the job has. for example if the images consist mostly of flesh tones of caucasion people then id say magenta and yellow should run last. if the job has lots of green grass, trees, and blue sky id say the cyan and yellow should be last cuz its the most dominant colors. saving the most dominant colors for last allows you the most control over the final product. the toughest part of this when running on a 2 color would be to try and be sure the yellow ink runs with something that makes it visable to the eye. yellow ink variations are very hard to see with the eye. i dont know if you capable of it or not because its really old technology but back in the day the use of a color key as opposed to a matchpring or digital proof was much prefered because you could seperate the layers and arrange them to the sequence you were running. there is even a little of an advantage to dry trapping a job 2 colors at a time and is actually prefered by some old school thinkin people. gladly im not one of them as i beleive any benefit is totally outweighed by the inherent problems that can occur. good luck in your old school endevours
     
  10. lildaddy50

    lildaddy50 Member

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    Notagroomer is correct once more, I swear to God I must have trained this guy. Run your black down fist then yellow on the first pass. Then ypu will have more room to match your color print on your second pass wth you cyan and mag.

    Rod (old school)
     
  11. Richie

    Richie Member

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    BYCM is the way to go you wont have much problem with colour matching, but at the same time it depends on the nature of the job(ink coverage of a certain in e.g. black solid etc).
     

  12. cityhunter

    cityhunter New Member

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    the correct sequence for 2 color press Cyan Magenta Black Yellow
    as for the density it depends on the ink to be used , there is no standard for the density and it should be based on the delta E value of each the process colors
     
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