Epson 8900 Series - Manual (Page 216)

Application Instructions A-3
q Valid Z-axis adjustment values are 00 through 99 from the
automatic Z-axis initialization adjustment (00) in positive or
negative directions (-99 through +99).
q Note the location of the Z-axis initialization whenever paper
stock is changed or tractors are moved, to determine the 00
calibration and corresponding number of sheets and form
thickness.
q Z-axis adjustments are not cumulative; each Z-axis adjustment
escape sequence is independent from previous adjustments in the
escape sequences referenced only to the 00 automatic calibration.
q Positive displacement moves the printhead away from the platen.
q The direction of printhead initialization displacement is positive.
To clear backlash, this requires that a negative displacement be
followed by positive displacement unless the adjustment for Z-axis
is reinitialization.
q The range of the printhead Z-axis adjustment from the control
panel is -5 through +20 from the Z-axis initialization adjustment.
q Each Z-axis adjustment requires that the printhead stop and
therefore acts to decrease throughput. Forms format and printing
format are both considerations to maximize throughput.
q Avoid a format that prints columns on either side of a label. If
printing a column is required, print the column first (but only to
the bottom of the label), adjust the printhead Z-axis while
reversing paper motion, and then print the label.
Caution: Care must be taken that a label is not peeled when
paper motion is reversed.
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