Use Enhanced to determine how the metafile is stored on disk. If Enhanced is true, the metafile is stored as an .EMF (Win32 Enhanced Metafile). If Enhanced is false, the metafile is stored as a .WMF (Windows 3.1 Metafile, with Aldus header). 

The in-memory format is always EMF. WMF has very limited capabilities; storing as WMF will lose information that would be retained by EMF. This property is set to match the metafile type when loaded from a stream or file. If loaded as WMF, then save as WMF.