decorative banner

Defining the knockout shape


    Use the Opacity & Mask Define Knockout Shape option to keep the 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 mask as a knockout group, 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 images.

    Note: The Opacity & Mask Define Knockout Shape option is most useful for objects that use a blending mode other than Normal.

    Illustration of knocking out shapes using a gradient mask with these callouts: A. Original objects B. Multiply blending mode applied to circle C. Circle with gradient added D. Both circles targeted and Make Opacity Mask selected in Transparency palette menu E. Star and circles grouped, and Knockout Group option applied F. Opacity & Mask Define Knockout Shape option applied to circle
    Knocking out shapes using a gradient mask A. Original objects B. Multiply blending mode applied to circle C. Circle with gradient added D. Both circles targeted and Make Opacity Mask selected in Transparency palette menu E. Star and circles grouped, and Knockout Group option applied F. Opacity & Mask Define Knockout Shape option applied to circle
    Illustration of knocking out shapes using a raster image with these callouts: A. Guitar raster image with transparent pixels and Color Burn blending mode B. Ellipse and guitar grouped and Knockout Group option applied C. Opacity & Mask Define Knockout shape option applied to guitar
    Knocking out shapes using a raster image A. Guitar raster image with transparent pixels and Color Burn blending mode B. Ellipse and guitar grouped and Knockout Group option applied C. Opacity & Mask Define Knockout shape option applied to guitar

To define a knockout shape:

  1. Group the objects you want to knockout.
  2. Select the group using the selection tool, or target it in the Layers palette.
  3. In the Transparency palette, select Knockout Group.
  4. Among the grouped objects, select the one that you want to reshape according to its opacity.
  5. In the Transparency palette, select Opacity & Mask Define Knockout Shape.