Creating transparency knockouts


    You use the Knockout Group option in the Transparency palette to make every object of the targeted group or layer knock out--that is, visually block--the areas of other objects in the group or layer that it overlays. Only artwork within the targeted group or layer is knocked out. Objects beneath the targeted group or in different layers are still visible relative to the group or layer.

    Selecting the Knockout Group option cycles it through three states: on (check mark), off (no mark), and neutral (square). Use the neutral option when you want to group artwork without interfering with the knockout behavior determined by the enclosing layer or group. Use the off option when you want to ensure that a layer or a group of transparent objects will never knock each other out.

    Group with Knockout Group option deselected (left) compared to selected (right)
    Group with Knockout Group option deselected (left) compared to selected (right)

To view the Transparency options:

    Choose Show Options from the Transparency palette menu.

To knock out objects within a group or layer:

  1. In the Layers palette, select the target icon to the right of a group, layer, or sublayer.
  2. Do one of the following in the Transparency palette:
    • Select Knockout Group to turn it on (check mark).
    • To use the Knockout Group option without interfering with the knockout behavior set by an enclosing group or layer, select Knockout Group until it displays neutral (square).

To prevent objects from knocking out within a knockout group or layer:

  1. In the Layers palette, select the target icon to the right of a group, layer, or sublayer.
  2. In the Transparency palette, deselect Knockout Group to turn it off (no mark).

To make an object's transparent strokes or fills knock each other out:

  1. Select the object.
  2. In the Transparency palette, select Knockout Group to turn it on (check mark).