Oce Arizona 640 GT, User Manual

Page: 109 / 230

How to Determine the Media Advance Correction
Factor
Introduction
When you print on roll media, there can be discrepancies in the amount the media advanced
during each print swath. This is referred to as media stepping. It can cause banding to occur, in
the form of either dark lines or white gaps. The figure below illustrates this banding.
[74] Media Advance Banding
• A) Understep can result in dark lines, where the media has not advanced enough and the
placement of a swath overlaps the prior swath. This requires a higher correction factor.
• B) Overstep can result in white gaps, where the placement of a swath is displaced a significant
distance away from the prior swath. This requires a lower correction factor.
• C) Perfect Step, where media advances correctly. This requires no change.
Purpose
The Media Advance Correction Factor (MACF) allows the operator to fine-tune media stepping
and to optimize print quality.
When to do
The MACF is only required when this particular banding occurs. If you don't see any banding in
your images, there is no need to change the value from its default setting of 50.
Before you begin
It is critical to load the media so that the media edge on the feed and take-up rolls are aligned
within 1mm.
How You Determine the MACF
In the 'Roll Media Manager' menu you can select the 'Media Advance Correction Factor' (MACF)
and enter a value from 0 to 100. The default value is 50. You can enter a lower value to correct for
white gaps or raise the value to correct for dark lines.
.
Procedure
1. Put several instances of the MACF print in the print queue.
2. Print with a default MACF of 50 (adjusted in Roll Media Manager).
3. If white lines appear, the media is overstepping. Gradually decrease the MACF until the white
lines start to disappear. Make a note of the MACF value. Continue to decrease the MACF until
dark lines just start to appear, and note the value. Typically, the average of these two is the ideal
MACF for this media.
4.
Similarly, if dark lines appear lines appear, the media is under-stepping. Gradually increase the
MACF until the dark lines start to disappear. Make a note of the MACF value. Continue to increase
How to Determine the Media Advance Correction Factor
Chapter 7 - How to Operate the Roll Media Option 109
Océ Arizona 600 Series