In AutoCAD 2008 you can automatically fade locked layers so that they are visible yet faded in comparison to the unlocked layers. This layer locking and fading functionality has been incorporated into the Layer Isolate tool. For example, if you are editing the Lighting and Power plans in a drawing, you can use the layer isolate tool, which is available on the Layers panel of the Dashboard, to select objects on the Lighting and Power layers. The new settings option enables you to lock and fade the other layers rather than just turning them off. You can specify a fade value; the higher the value, the more faded the layers will become. A slider bar in the Layers panel of the Dashboard enables you to modify the fade value.
As the name implies, selecting the lock and fade option in the layer isolate tool not only fades the layers but it also locks them. You can use the Layer Unisolate tool, available on the Dashboard, to restore the display to its previous settings.
Even if you manually lock layers as opposed to using the Layer Isolate tool, you can take advantage of the fading capability.