For printing on glass or dark (e.g. black forex) material, it is often necessary to print a white undercoat. You can create a white undercoat with the Generate White tool.
Instead of white, you can also use other special inks such as Metallic ink or Varnish to create an extra coating or finishing effect.
How to create a white undercoat
  1. Click the Generate White white tool on the Tools panel.
  2. Select the White Method option Flood to print the document with a white undercoat.
    white-gen
  3. Define the White Amount, that is, the percentage of the special ink.
  4.  Select the Spread / Choke.
  5.  Select the presentation of the White Color from the drop-down list. This can be any color channel available on the output device.
  6. Click OK. The white undercoat is set up in a separate layer.
    Special ink application methods
    The following table lists the possible application methods and delivers a short description.
    • Flood: fills the whole document with a white base layer
    • Fill all selected: (Selection must be done before opening the dialog) fills the selected area with a white base layer
    • Under color: prints white under parts that contain image
    • Under white: prints white under non-image areas
    • Transparency: uses the information in the image’s alpha channel if present
    • Density: fills with white ink relative to the density of the image, the more density in the image the lesser white ink is used
    • White amount: the percentage of white ink generated

    Choke/Spread

    In case the white generated object needs to be larger/smaller than the actual object, the Spread (to enlarge the white object) or Choke (to shrink the white object) need to be used.

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    When selecting one of these options, it is necessary to also input a value for the Spread/Choke.

    Depending on the document, certain values of Spread/Choke may not provide the desired results. In this case, it is recommended to:

    1. Undo the last action performed

    2. Generate the white layer with spread/choke using alternative values (as close to the desired value as possible)

    3. Repeat steps #1 and #2 if the new results are not as expected.