Oki IP-7900-21 Advanced Operation Manual page 95

STEP 3 Print [BACK ADJ PRINT] again to check that the horizontal lines overlap on the print pattern.
Perform STEP 1 and STEP 2 until the horizontal lines on the print pattern overlap.
1
Validate the media back feed adjustment pattern
Determine the adjustment value so that the pattern's horizontal lines overlap.
If the value is larger, the upper and lower patterns overlap at the center.
If the value is smaller, the upper and lower patterns show a gap.
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