Generating CTP correction curves based on existing plate curves

This page describes fine-tuning 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 Basic or higher license level
  • MeasureColor CTP combi color bar eci_grayconm_i1_fogra39.pdf
  • A compliant measurement device (X-Rite EyeOne, X-Rite eXact, Konica-Minolta MYIRO, 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:

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’
  • Analyze the result in the ‘Gamut’ view and check if the solids and overprint values match the chosen standard
  • Analyze 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.
  • 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 analyze the printed curves and (automatically) calculate CTP corrections.
  • To import an existing curve, click on the ‘Load curve’ button and import the curve file you created earlier – A pop in 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 into your Prepress system. To check the results, perform a standard quality check as described in the QuickStart document analyzing print quality.