AutoCAD 2008 User's Guide > Share Data Between Drawings and Applications > Work with Data in Other Formats > Import, Attach, or Open Other File Formats > Attach DGN Files as Underlays > Attach and Detach DGN Underlays > 
Detach DGN Underlays
Concept Procedure Quick Reference
 
 
 

DGN underlays can be detached from a drawing file.

You can detach DGN underlays that are no longer needed in a drawing. When you detach a DGN underlay, all instances of the underlay are removed from the drawing, the underlay definition is purged, and the linking path to the DGN file is removed.

To hide the display of a DGN underlay temporarily, you can unload it rather than detach it. This action preserves the DGN underlay and its location for reloading later.

NoteErasing an individual instance of a DGN underlay is not the same as detaching it. A DGN underlay must be detached to remove the link from your drawing to the DGN file.