Canon PRO-10 Series Manual page 560

Do not open the top cover while printing is in progress.
8.
Check the printed pattern
Enter the numbers of the patterns with the least amount of streaks in the associated boxes, and click
OK.
Note
If it is difficult to pick the best pattern, pick the setting that produces the least noticeable vertical
white streaks.
(A) Least noticeable vertical white streaks
(B) Most noticeable vertical white streaks
9.
Confirm the displayed message and click OK
The second pattern is printed.
Important
Do not open the top cover while printing is in progress.
10.
Check the printed pattern
Enter the numbers of the patterns with the least amount of streaks in the associated boxes, and click
OK.