If you want to make an exact copy of one of your libraries, either as a backup or as part of moving a library to another disk, you can do so one of two ways.

• Choose the library you want to copy and choose the "Duplicate Library" command from the File menu. You will be prompted to choose a location to store the new copy of the library. iPhoto Library Manager will copy the library and, when it's done, it will automatically appear in your library list. If you are running OS X 10.4 or later, iPhoto Library Manager will also automatically tell Spotlight to index the new copy of the library.
• Choose the library you want to copy and click the "Reveal In Finder" button on the right. You can then use the Finder to copy the entire library folder to the location you want the copy to be. After it is done, if you want to work with that library in iPhoto Library Manager, add it to your library list.

See also:

Creating a new library

Adding a library

Removing a library

Moving a library

Renaming a library