Generating CTP correction curves based on existing plate curves

This page describes how to fine tune your existing CTP curve ('curve-on-curve'). If you need to generate a CTP correction curve based on linear plates look here: generate CTP correction curves based on linear plates

What you need:

  • MeasureColor 4 Basic or higher license level
  • MeasureColor CTP combi color bar eci_grayconm_i1_fogra39.pdf
  • Compliant measurement device (XRite EyeOne, XRite 530939, XRite SpectroEye, Techkon SpectroDens, Techkon SpectroJet (Measurement devices like the XRite Intellitrax and Techkon SpectroDrive are less suited for this task)

Generic preparations:

  • Embed the ‘MeasureColor CTP combi’ color bar in a test form or production job, make sure it is aligned vertically (printing direction)
  • Generate the printing plates based on your current CTP curve
  • Print the form according to your standard for solid inks
  • Let the printed sheet dry if applicable

Special preparations:

  • Export the current used CTP curve from a MeasureColor supported prepress system to a file
  • MeasureColor currently supports Agfa Apogee, GMG ColorServer and Kodak Harmony (Prinergy) systems

MeasureColor workflow:

  • Open the ‘ProcessControl Module’
  • Create a new job based on the proper reference and make sure the ‘MeasureColor CTP combi’ color bar is selected for this job
  • Measure the color bar and hit ‘Finish’
  • Analyse the result in the ‘Gamut’ view and check if the solids and overprint values match the chosen standard
  • Analyse the result in the ‘Dot gain’ view and check that there are no odd results. TVI curves should look natural but might be too high or too low of course.
  • If printed solids and overprint are OK and the TVI curves show no strange behaviors, it is time to generate the actual CTP compensation curve
  • Switch to the ‘CTP’ view. This is where we analyse the printed curves and (automatically) calculated CTP corrections.
  • To import an existing curve, click on the ‘Load curve’ button and import the curve file you created earlier - A popin view is presented. Check if all colors are mapped correctly and adjust if necessary
  • All CTP corrections will be calculated based on your existing curve, finetuning it to match your print standard
  • To save a CTP correction curve in a native format, click on the ‘Save curve’ button
  • Set the file name and location and choose the format for your workflow: Agfa Apogee, GMG ColorServer, Kodak Harmony (Prinergy) - Save the file to disk

You can now import the generated CTP curve in your Prepress system. To check the results, perform a standard quality check as described in the QuickStart document analysing print quality.