Patterning is the repeated placement of a hatch line or cell through a closed area at a specified interval (spacing), scale, and angle. You can place patterns on any designated level.

In DWG workmode, by default, area patterning is replaced by AutoCAD pre-defined hatching.

The Pattern field in the Pattern Area tool settings window, by default, lists the patterns in the DWG pattern file areapat.pat. This file contains a DWG pattern definition for each pattern cell in the supplied cell library, areapat.cel.

To select a different DWG pattern file, key in its full file specification — path and filename — in Pattern File or click the adjacent browse icon to browse the file system.

A corresponding DWG pattern file is supplied for each of the supplied pattern cell libraries, such as archpat.cel, areapat.cel, geompa.cel, igespats.cel, linepa.cell, and utilpat.cel. These DWG pattern files have the same filename as their cell library counterparts, except their extension is .pat.

When a pattern uses a line style that is not solid, saving as DWG will drop it to an anonymous block with a name prefix "*X".