The Layers palette lets you hide layers, sublayers, or individual objects from view. When a layer is hidden, objects on the layer are also locked and cannot be selected or printed. You can also use the Layers palette to display layers or objects in either Preview or Outline view independently from other layers in the artwork.
Now you'll edit the frame on the clock, using a painting technique to create a three-dimensional effect on the frame.
In the Layers palette, click the Frame layer to select it, and then Alt-click (Windows) or Option-click (Mac OS) the eye icon next to the Frame layer name to hide the other layers. Alt/Option-clicking the layer eye icon alternately hides and shows a layer. Hiding layers also locks them ...