Correct colour shift or mottles for media

In prints of some media, a colour shift or mottles can appear. You can correct this with the following procedure.

Procedure

1. Touch [System]  → [Media] .

2. Select the media from the media catalogue.

3. Touch [Optimise].

4. Touch the [Determine secondary transfer voltage] procedure.

   

5. Select [Small range] in the [Select parameter value range] field to print a small range of patches with secondary transfer voltage parameters.

6. Select [2-sided] in the [Print sides] field when the surface type of the front side differs from the back side.

7. Touch [OK].

8. Follow the instructions on the control panel.

   1. Take the test charts.

      The current values of the secondary transfer voltage parameters are printed in a different colour.

      Example of test charts (wide range of patches, A3, 1-sided)

      In the above figure is the current value of the secondary transfer voltage parameter 0. The patch with the optimal print quality is -13.

   2. Identify the patches that have the optimal print quality.

      When a series of patches show the optimal print quality, take the middle value.

      When the patches do not show the optimal print quality, touch [Finish] and redo the procedure with the [Wide range] option.

      When you printed 2-sided test charts, examine the front side and back side.

      The front side charts shows a single asterisk symbol (*) between the values. The back side charts show two asterisk symbols (**) between the values. The current parameter values are printed in a different colour.

   3. Remember the parameter values of the patch with the optimal print quality. In this example: -13.

   4. Touch [Finish] to close the wizard.

      Select the[Wide range] parameter in the [Select parameter value range] field to print a wide range of patches with secondary transfer voltage parameters.

9. Go to: [Front side parameters]  → [Determine secondary transfer voltage] .

10. Enter the determined parameter value. In this example: -13.

    Parameter value for secondary transfer voltage of the front side

11. Go to: [Back side parameters]  → [Determine secondary transfer voltage] .

12. Enter the determined parameter value. In this example: -13.

    Parameter value for secondary transfer voltage of the back side

13. Touch [OK] to store the specified values of the secondary transfer voltage parameters.

    IMPORTANT

    When you perform the [Determine secondary transfer voltage] procedure without clicking [OK], then the specified parameter values are not used.

Result

When you perform the [Determine secondary transfer voltage] procedure again, then the new set values of the secondary transfer voltage parameters are printed in a different colour.

Example of test charts (wide range of patches, A3, 1-sided) where the current parameter value is 0.

More information

• Calibrate the printer

• Calibrate a media family

• Perform a shading correction