Canon MX520 series Online Manual page 94

Important
Do not touch any printed part on the print head alignment sheet.
Be careful not to get the print head alignment sheet dirty. If the sheet is stained or wrinkled,
it may not be scanned properly.
(6) When the message "Did the patterns print correctly?" appears, confirm that
the pattern is printed correctly, select Yes, then press the OK button.
5. Scan the print head alignment sheet to adjust the print head position.
(1) Confirm the message, then load the print head alignment sheet on the platen
glass.
Load the print head alignment sheet WITH THE PRINTED SIDE FACING DOWN and align the
mark on the upper left corner of the sheet with the alignment mark .