Canon imagePROGRAF TA-20 MFP 24" Large Format Printer with L24ei Scanner and Stand Kit - Manual (Page 363)

7. Examine the test pattern for adjustment. Determine the straightest set of lines.
Example 1: Select "+2" in pattern (C).
Example 2: Move the angle adjustment lever to a position between the numbers or between the number
and the square (D) of the two sets of lines that are least misaligned. In this case, select -1.
8. Open top cover and move angle adjustment lever to match number (or square) of
straightest set of lines.
9. Close the top cover.
The print head is now straight, and adjustment is complete.
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