Activity 4: Use a print curve to align a press with an industry specification for tonal match

Background

A print calibration curve makes the response of a halftone output device condition match either the tonal response or the gray balance of a target device condition.

You can use print calibration curves to align a curve-controlled device with an industry specification. This activity is to create a print calibration curve to align a press with an industry specification for tonal match. Tonal match refers to Tone Value Increase (TVI), also known as dot gain, and uses the calculated Effective Dot Area (EDA) for calibration. Calculations are based on the density measurements of each ink or colorant.

When using a ColorFlow curve for tonal calibration in Prinergy, you can make on-the-fly tonal adjustments.

Tasks

Goal
Create a print calibration curve and define an industry specification as your target. After the curve is created, use the print curve to output a job in Prinergy and make an one-the-fly tonal adjustment.

Task 1: Create a print calibration curve to match an industry specification 

1. In ColorFlow, click the Print Curves tab.
2. In the Calibration Curves section, click the Add button  .
3. In the Device dialog box, add a new device: 
   1. In the Device Name box, enter XX Offset Press (where XX= your initials).
   2. From the Device Type list, choose Offset Press-Sheetfed.
   3. Click Create.
   4. Drag the device you just created to the viewer window.
4. Click the Properties icon .
5. From the Plate Setup list, choose the Kodak Thermal Gold, 20u Staccato, Offset Press Sheetfed plate that you added in a previous activity. If it doesn't exist, add the plate:
   1. Click the Add button   next to Plate Setup.
   2. In the Plate Type box, select  Kodak Thermal Gold or add the value to the list if it doesn't exist.
   3. In the Screening box, select  20u Staccato  or add the value to the list if it doesn't exist.
   4. In the Plate Line box, select  Trendsetter  or add the value to the list if it doesn't exist.
      
6. From the Substrate list, choose Type 1 or 2 (coated art) 170 g/m2.
7. Click OK.
8. Create a Tint Ramp chart:
   1. Click the Measurement icon
   2. In the Charts section, click the Add button
   3. A chart appears in the Charts list with a default name.
   4. From the Chart Type list, choose Tint Ramp. 
   5. In the Tint Set section, click the Edit button
   6. Click the Add button 
   7.   and enter 0 10 25 50 75 90 100.
   8. Click OK.
   9. From the Process Ink Set list, choose CMYK.
   10. Click Save.
9. Enter the measurement values. In a real-life situation, you might need to print the chart and measure the chart using a measurement device. For the purpose of this training, you enter the given EDA values:
   1. Click Measure.
   2. From the Print Curve list, choose Linear (None).
   3. Click Enter manually.
   4. In the Channel Binding section, click C, M, Y, K Same.

   5. In the Tonal  Response section, enter the following EDA values:

      Tint in	EDA
      0	0
      10	12
      25	29
      50	57
      75	82
      90	93
      100	100

   6. Click OK.

10. To review the measurement value:
    1. Click the Measurements tab.
    2. Select the chart and click View.
    3. Select the Show Measurements check box.
       You should be able to view and edit the measurement value in the Tonal Response section. 

    4. Close the Device Measurements dialog box.

11. Define the conversion target to an industry specification:
    1. Click the Conversion icon 
    2. .Select the Show curves in Prinergy check box.

    3. Click the Process Inks tab and choose GRACoL 2006 Coated 1 from the Target list.

    4. From the Curves Method list, choose Tonal Match.
12. Click OK.
    A print calibration curve is generated to match the chosen industry standard. 
13. In the Calibration Curves table list, find the curve and double-click the default curve name and enter XX new print calibration curve for tonal match (where xx= your initials).

Task 2: Output a job using the newly created print calibration curve

1. In Prinergy, create a new job, and name it as XX tonal match (where XX = your initials).
2. Refine Chart_TintRamp_CMYK.pdf with 1stRef-Normz.
3. Output the PDF file using Virtual Proof.LoosePage with the print curve you just created:
   
   1. In your Virtual Proof.LoosePage Process template dialog box, from the Output To list, choose Virtual Proof.
   2. Leave ColorFLow Color Relationship Management unchecked.
   3. Expand the Calibration & Screening panel.
   4. Click the ColorFlow Current State radio button.
   5. Expand the Print Curve drop down list and select curve XX new print calibration curve for tonal match .
4. Open the generated page in VPS and measure the 10%, 25%, 50%, 75%, and 90% black patch. 
   Confirm that the plate calibration curve has been applied: 10% measures 15.5; 25% measures 35.9; 50% measures 61.8; 75% measures 84.4; 90% measures 95.5.

Task 3: Make an on-the-fly tonal adjustment in Prinergy 

1. In Prinergy, start a final output process using the same process template used in Task 2.
2. In the Start Process dialog box, click Tonal Control.
   The Tonal Control dialog box appears showing the information from the separations in the surfaces of the job selected for output.
3. From the Separation list, select Black.
4. The Curve Channel list displays the ColorFlow curve channel that has been assigned for the selected separation. From the Curve Channel list, choose Black.
5. To make tonal adjustments, in the Tonal Adjustments section, drag the sliders or enter the desired values directly into the boxes under the sliders. The  Midtone (50%)  control affects the full tonal range. If you adjust the Midtone (50%), the Quartertone (25%), the 3/4 Tone (75%, the Highlight (10%), and the Shadow (90%) are adjusted according to the value of the Midtone (50%).  For the purpose of this training, in the box under the  Midtone (50%)  slider, enter  -5 .
6. Click OK.
7. After the output is done, open the generated page in VPS and measure the 10%, 25%, 50%, 75%, and 90% black patch.
   Confirm that the tonal adjustments you made are applied: 10% measures 14.1; 25% measures 32.5; 50% measures 56.8; 75% measures 81; 90% measures 94.1.

Outcome

You have created a print calibration curve for tonal match and made an on-the-fly tonal adjustment in Prinergy.