You can turn layers on and off in an underlay.
By default, all visible layers of an underlay are turned on when you attach the file. It is usually convenient to turn off
any unneeded layers to reduce the visual complexity of your work.
Use the DWFLAYERS, PDFLAYERS, DGNLAYERS, or ULAYERS command or right-click a selected underlay and click Layers on the shortcut
If the Underlay Layers dialog box is empty, there are no layers in the underlay.
You can use the Properties palette to determine whether any layers are turned off in an underlay.
- If no layers are turned off, the Layer Display Override property is set to None.
- If at least one layer is turned off, the Layer Display Override property is set to Applied.