Opacity

This effect changes the degree to which objects are opaque or transparent. It specifies the opacity of selected objects. When you change the opacity of an object to which a Box effect was applied, the opacity of the box will not change.

To apply the opacity effect:

1.  Select an object to which you would like to apply the effect.

2.  Choose the Opacity command from the Effects menu or click the Opacity button on the Effects palette, then choose the desired percentage between 10 and 100 from the submenu. You can experiment with the percentage in order to get the necessary degree of transparency for your object.

NOTE: You can always use the Undo command from the Edit menu to discard the last effect applied to your object.

Refer to the following topic for more information:

Color, Tint and Opacity

Effects Palette