You are asking “Sam, what custom tab?” Select Hatch on the Ribbon (or type Hatch at the command prompt) then T for Settings. Let us now add some extra patterns to the custom tab. You can give your patterns a name with the format *MYNAME, DESCRIPTION followed by the pattern as shown below in the EARTH example.Example of the Earth You can edit the default PAT files that are installed with AutoCAD by using Notepad and adding your custom hatch pattern data at the end of the file. Hatch patterns are stored in a file named ACAD.PAT or ACADISO.PAT. Recently I have had several people ask me about the custom hatch pattern tab in AutoCAD and how to populate that tab with your custom patterns.