Illustrator

Use transparency to shape a knockout

You can use the Opacity & Mask Define Knockout Shape option to make a knockout effect proportional to the object’s opacity. In areas of the mask that are close to 100% opacity, the knockout effect will be strong; in areas with less opacity, the knockout effect will be weaker. For example, if you use a gradient-masked object as a knockout, the underlying object will be knocked out progressively, as if it were being shaded by a gradient. You can create knockout shapes with both vector and raster objects. This technique is most useful for objects that use a blending mode other than Normal.

  1. Do one of the following:

    • To use an opacity mask to shape the knockout, select the masked artwork, and then group it with the objects you want to knock out.

    • To use the alpha channel of a bitmap object to shape the knockout, select a bitmap object that contains transparency, and then group it with the objects you want to knock out.

  2. Select the group.
  3. In the Transparency panel, select Knockout Group until the option displays a checkmark.
  4. Among the grouped objects, target the masking objects or transparent image in the Layers panel.
  5. In the Transparency panel, select Opacity & Mask Define Knockout Shape.
    Knocking out shapes using a bitmap object

    A.
    Original artwork

    B.
    Darken blending mode applied to the word “PEARS”, and Group option selected

    C.
    Opacity & Mask Define Knockout shape option applied to word