To avoid putting too much ink onto the substrate, some print applications, such as gravure, require solid areas be screened. To screen solids you will need to create a “solid cutback” Transfer Curve in ColorFlow. The solid cutback curve can be used as is, or can be applied as a Print Curve to fingerprint your print condition and create a final Print Calibration curve.
Creating a solid cutback Transfer curve in ColorFlow is not an intuitive process, because you cannot use the default method of setting Tint In/Out Points (node-based editing).
Use the following method to create a solid cutback Transfer Curve.
- In the Print Curves tab, under Transfer Curves, click the Add button .
- Go to the Curve Parameters viewing panel on the right side of the window and enter specifications from top to bottom.
- Enter a name for your curve and leave the Show in Prinergy check box selected to make it visible in Prinergy.
- Under Device Condition, enter or select appropriate device condition values.
- Under Curve Channels, select One channel for CMYK or Separate Channels for CMYK, as appropriate. (If you eventually intend to align your print condition to an ISO standard or G7, you will need to select Separate Channels for CMYK.)
- Add any required Spot Inks. (You will have to click the Apply button to make any new Spot Inks visible under Curve Definition in the next step.)
- Under Curve Definition choose CMYK or Spot as appropriate. (If you’ve selected Separate channels for CMYK, you will need to repeat the following procedure for each C M Y K channel.)
- From the Curve Origin drop-down menu, click Custom Shape and click Apply.
- Now click the Adjust button at the bottom of the panel and click OK to accept the warning.
- In the Transfer Curve Adjustments panel that appears, click Transfer Curves.
- Click in the Tint In entry box, enter 100 and press Tab.
- The Tint In and Tint Out values will change to 99.90.
- In Tint Out, enter the desired solid cutback value (eg. 80%) and press Apply. The solid cutback curve has been created.
- Hit the Close button to return to the Transfer Curve Adjustments window. Hit OK to complete the process of creating a solid cutback curve.
- Note that if you hit the View… button at the bottom of the panel, the curve appears linear. The actual cutback curve is only visible in the Curve Adjustments panel after pressing the Adjust… button.
- In a Prinergy Output Process Template, choose ColorFlow Current State as the Curve Source and select the solid Cutback Transfer Curve.
- Also under Calibration and Screening in the Process Template, check the Screen Solids …as checkbox and enter the same value you entered in your solid cutback curve for 99.90 Tint Out. (eg. 80)
- Output your print target with the solid cutback curve applied.
- If you want to just make additional dot gain adjustments after measuring the printed target, you can do this by hitting the Adjust… button and moving the adjustment sliders for each channel.
- If you want to proceed to do make a Print Calibration Curve to align your print condition to a specific standard, hit the Add button under the Print Calibration Curves panel and create a new Device Condition.
- Press the button to open the Device Condition Properties panel, enter the appropriate properties and press OK.
- Hit the button, select the target you printed with the solid cutback curve, and press the Measure button.
- For Print Curve: select the solid cutback curve you applied when you output the target and proceed to measure the target.
- Press Close, hit the button on the Device Condition, choose the desired Target print condition and press OK.
- Make sure that Show curves in Prinergy is checked.
- Create a new output process template with the Print Curve you just created selected under ColorFlow Current State Curve Source.