Epson B 310N - Manual (Page 76)

Printing with Special Layout Options 76
& See “Accessing the Printer Driver for Mac OS X” on page 15.
2. Click the d button to extend this dialog.
3. Select the printer you are using as the Printer setting, and then make suitable settings.
Note:
Depending on your application, you may not be able to select some of the items in this dialog.
If so, click Page Setup on the File menu of your application, and then make suitable settings.