Creating and editing opacity masks


    An opacity mask uses a masking object to alter the transparency of the underlying artwork. Where the mask is white, the artwork is fully visible. Where the mask is black, the artwork is hidden. Shades of gray in the mask result in varying degrees of transparency in the artwork.

    Illustration of Creating an opacity mask with these callouts: A. Underlying objects B. Object with blending mode and transparency C. Object filled with black-to-white gradient D. C moved over the area of B and masking B
    Creating an opacity mask A. Underlying objects B. Object with blending mode and transparency C. Object filled with black-to-white gradient D. C moved over the area of B and masking B

    Once the opacity mask is created, a thumbnail of the masking object appears in the Transparency palette to the right of the thumbnail of the masked objects; by default, these objects are linked (as shown by a link between the thumbnails in the palette). When masked objects are moved, the masking objects move along with them; when masking objects are moved, the masked objects don't move. You can unlink the mask in the Transparency palette to lock the mask in place and move the masked objects independent of it.

    Transparency palette displays opacity mask thumbnails: left thumbnail represents masked objects, right thumbnail represents masking objects
    Transparency palette displays opacity mask thumbnails: left thumbnail represents masked objects, right thumbnail represents masking objects

    Tip iconYou can create an opacity mask from virtually any object imaginable, including a gradient, mesh, or pattern. (See Working with gradients, meshes, and blends.)

To create an opacity mask:

    Do one of the following:

    • Select at least two objects or groups, and choose Make Opacity Mask from the Transparency palette menu. The topmost selected object or group is used as the mask.
    • Select a single object or group, or select a layer's target icon in the Layers palette, and then, in the Transparency palette, double-click the mask thumbnail area (directly to the right of the object thumbnail). An empty mask is created and Illustrator automatically enters mask-editing mode. Use the drawing tools to draw a mask shape.

    Note: The Clip option sets the mask background to black. Therefore, black objects, such as black type, used to create an opacity mask with the Clip option selected will not be visible. To see the objects, use a different color or deselect the Clip option.

To unlink or relink a mask:

    Target the mask in the Layers palette, and then do one of the following:

    • To unlink the mask, click the link symbol Link symbol between the artwork thumbnail and the mask thumbnail in the Transparency palette, or choose Unlink Opacity Mask from the Transparency palette menu. The masking object is locked in position and size, and the masked objects can be moved and resized independently of the mask.
    • To relink the mask, either click the area between the thumbnails in the Transparency platter or choose Link Opacity Mask in the Transparency palette menu.

To edit an opacity mask:

  1. Do one of the following to enter mask-editing mode:
    • Click on the mask thumbnail in the Transparency palette.
    • Alt-click (Windows) or Option-click (Mac OS) on a mask thumbnail to view only the mask in the document window.
  2. Use any of the Illustrator editing tools and techniques to edit the mask. Changes made to the mask are immediately visible in the Transparency palette.
  3. Click the artwork thumbnail in the Transparency palette to exit mask-editing mode.

To deactivate an opacity mask:

  1. Select the target icon to the right of the mask in the Layers palette. (The palette displays a dotted line underneath the mask listing.)
  2. Do one of the following:
    • Shift-click the mask thumbnail (right thumbnail) in the Transparency palette. To reactivate the mask, shift-click the mask thumbnail.
    • Choose Disable Opacity Mask from the Transparency palette menu. To reactivate the mask, choose Enable Opacity Mask from the Transparency palette menu.

    When the opacity mask is deactivated, a red x appears over the mask thumbnail in the Transparency palette.

To remove an opacity mask:

  1. Select the target icon to the right of the opacity mask or a masked object in the Layers palette.
  2. Choose Release Opacity Mask from the Transparency palette menu to remove the mask. The contents of the mask will appear on top of the objects that were masked.