you might want to do a search at the gimptalk site for more info about macs and gimp. You might also want to take a look at the Folders tab in the Preferences Window (You access the Preferences through the menu Edit->Preferences). Expanding the Folders will bring up more options, including Patterns. Click that and I hope you get the location of the Gimp folder(s) where the patterns are stored. At least you do on a windows machine, but I don't see the interface to be THAT different on a mac....I hope that helps