Please go to this page and type in alignment if you are on Mac. The instructions below are for Windows OS.
Performing the Print Head Alignment - iP1600 (Windows)
1. First, load a sheet of A4 or Letter size plain paper in the Auto Sheet Feeder and then open the Properties
For Windows XP Home Edition
Click/Select 'Start' from the bottom left of the Windows screen, 'Control Panel,' 'Printers and Other Hardware,' and 'Printers and Faxes.'
For Windows XP Professional Edition
Click 'Start' from the bottom left of the Windows screen, and 'Printers and Faxes.'
For Windows 2000/Me/98
Click/Select 'Start' from the bottom left of the Windows screen, and 'Settings,' then 'Printers.'
2. Select the 'Maintenance' tab.
3. Click the 'Print Head Alignment' button.
4. Click 'OK'. The pattern will be printed.
5. After the pattern is printed, click 'Yes'.
Align the Print Head
1. Look at the printout. From the patterns, select the most even and least irregular patterns.
2. Enter the numbers.
3. Click 'OK'.
The Canon page contains graphics, and can be reached in the same fashion as indicated above if you need those.
Please post back if you need further help, otherwise thank you for using and rating FixYa!