Color Print Training - Part 1

Discussion in '4-Color Offset Presses +' started by DanRemaley, Apr 7, 2023.

  1. DanRemaley

    DanRemaley Senior Member

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    I am retired from the industry but have a lot of information you may find useful.

    Im going to present color training through System Brunner's concepts. I hope to get Press & Pre-Press to work together and I will give you measurable numbers to focus on. You can contact me anytime via email, phone or text. Please ask questions if you don't understand - others may have the same questions.

    I presented a 'Process Control Boot Camp' at GATF - if you attended you will already know this information!

    Dan Remaley

    412.889.7643

    danremaley@comcast.net


    Part 1 is related on how we measure and control color. Brunner says that 90% of Printing problems are caused by "Dots", only 10% by solids - so - hum - when measuring Density or Lab we're controlling 10% to the problem!!
     

    Attached Files:

  2. DanRemaley

    DanRemaley Senior Member

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    Color Training - Part 1


    PC Reference - shows Grey Balance with 2/4/6% increase of each color (casted). Other patches show all colors increase or decrease - still acceptable.

    CMC Chart - Shows elliptical shape of color. Notice where Grey is - right in the middle, smallest ellipse.

    Solid colors are the largest ellipse. Note humans are more tolerant of Greens than Red’s!!

    Rhem Indicators- Use these check areas that are used for viewing color - Press area, conference room, etc. 2-stripes shows a (red cast) 3-stripes show a (blue cast).

    Isochromatic Test- checks for color blindness - 1 of every 8 men are color blind!
     

    Attached Files:

  3. DanRemaley

    DanRemaley Senior Member

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    Color Training Brunner- Part 2

    See the problem is that we print “Dots” not Solids, so we need to measure Dots and in turn Grey Balance.

    The Pressroom ‘thinks’ that they “control” color - nothing could be further from the truth!

    They can’t change the dots on the plates - only prepress can!!

    So every RIP maker has a file called “Wanted Values” and “Measured Values” - ever notice that they don’t supply the “Wanted Values”? Well I have them and will share with you - I averaged several hundred printed sheets printed near SWOP/Gracol targets and created a complete Grey Balanced Tone Scale for the pressroom - however we need to determine what YOUR “Measure Values” are by running linear or current values.

    You see printing is pretty simple - you can only print in 2 places - in “Gray Balance” or “Casted”.

    Whoops, sorry, you can only print in only ONE place - GREY BALANCE - casted doesn’t look so good!


    Brunner Items- He explains why measuring in Lab is problematic. He also addresses the “picture class” theory - same as CMC tolerance but with pictures.
     

    Attached Files:

  4. DanRemaley

    DanRemaley Senior Member

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    Color Control 3- Controlling color, Grey Balance, color bars.

    Grey Balance Offset/Web- I have supplied the method and the numbers that are needed to print to Grey Balance.

    I supplied 2 color bars for run control.
     

    Attached Files:

  5. DanRemaley

    DanRemaley Senior Member

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    Pressroom#1-

    Rhem Indicators-Use these check areas that are used for viewing color - Press area, conference room, etc. 2-stripes shows a (red cast) 3-stripes show a (blue cast).

    PC Reference - shows Grey Balance with 2/4/6% increase of each color (casted). Other patches show all colors increase or decrease - still acceptable.

    Grey Balance Offset/Web- I have supplied the method and the numbers that are needed to print to Grey Balance.

    I supplied 2 color bars for run control.

    We now know that its impossible to print well with ‘linear plates’ or with only ‘one curve’. We need 4 distinct curves for Grey Balance at press
     

    Attached Files:

  6. DanRemaley

    DanRemaley Senior Member

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    Pressroom#2-

    Press Test- The press should be gone over with all settings checked, new blankets, water, etc. Read the attached files for a Press Test.

    Grey Balance Evaluation-

    The first set of linear plates are run to density, measured above the tone scale. For this press run you don’t need to have all the correct densities on one sheet, they can be on 4 different sheets, we are only measuring the density and tone scale of every color. (Pictures are only tone scales mixed up!). Same process for uncoated but different density numbers.

    After the dot area measurements are added to the RIP and the “Wanted dot area numbers” are entered, the plates will be adjusted for the correct tonality, by the RIP.

    Now we need all the densities on the same sheet correct, to evaluate the dot gain and Grey Balance. Sometimes the curve needs a minor adjustment but 80% of the time its fine - the dot gain numbers on press should match the wanted 25-50-75% patches. Use the 2-Tier Color Bar for evaluation.

    I have included the density for uncoated as well - the target dot gain is the same as coated!! Ever wonder why uncoated looks ‘muddy’? Its because the paper absorbs the ink and increases the dot gain so you can’t add ink - not anymore!!
     

    Attached Files:

  7. DanRemaley

    DanRemaley Senior Member

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    If anyone would like information regarding the reference material, please contact me directly.The attached item is to create plate curves for any press, Sheetfed or Web.
    I measured many sheets to come up with these dot area numbers, I am sharing them with you, to become a better printer! I have included the numbers for uncoated - it will be the best uncoated sheet you ever printed! Comments/Questions?

    Dan 412.889.7643
     

    Attached Files:

    asem alsafady likes this.
  8. Ryu Hades

    Ryu Hades New Member

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    Thank you for sharing it. I always looking forward much information about you.
     
  9. DanRemaley

    DanRemaley Senior Member

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    Were you able to download files?
    Email me directly - I can send you more.
    Danremaley@comcast.net
     
    asem alsafady and Ryu Hades like this.
  10. DanRemaley

    DanRemaley Senior Member

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  11. Ade

    Ade Member

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    If you are doing any plate changes you need to ensure the press is in order, rollers set properly, new packing and blankets, cleaned and flushed techno trans, techno trans solution is correct, otherwise you are wasting your time, if the press isn't set up correctly.
     

  12. DanRemaley

    DanRemaley Senior Member

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    Absolutely true - new blankets/ water, etc.
     

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