Symptom
Vertical streaking is observed, as shown in the image:
Considerations
- This issue is not present on all materials, occurring only on 3M 180Cv3-10 with a production setting of 360x360, using CMYKcmk (as depicted in the picture).
- There are minimal ink restrictions (see image).
- The issue persists even with CMS disabled.
Problem
The problem is likely related to dot distribution and the specific print mode used.
Solution
Starting with Version 9.20, Revision B of the Seiko-M-64S driver, a "New dot distribution" option was added.
To address the issue, enable the "New dot distribution" setting in EasyMedia when creating a new profile, as this option requires the creation of a new profile:
Additional Information on "New Dot Distribution"
After enabling the "New dot distribution" option, some changes in the printing output may occur.
Effect on Dot Distribution
This advanced option affects dot distribution by manipulating drop sizes and density ratios. It is comparable to controlling dark/light transitions, utilizing three curves: small, medium, and large drops in vardot, distributing 1, 2, or 3 drops at the same pixel in multi-drop configurations.
An exception exists for the Quality resolution (540 dpi), which is limited to a maximum of 2 drops per pixel.
Density Ratios
The density ratios are hardcoded in the printer driver; the parameter alters the height of the curve in percentage for small (3/1) and medium (3/2) drop sizes, with only the 3/1 option applicable for Quality resolution.
Typical values around 60-80% are recommended, but if overlapping of drops is inadequate, leading to banding issues, adjusting to 50% may provide improvements.
Resolution Considerations
For resolutions of 720 dpi or higher, only a single drop is utilized, permitting the use of error diffusion screening as well.
Customer feedback has indicated that operating at 720 dpi initially helped mitigate the problem. After reverting to 540 dpi while employing the "new dot distribution" option with a 3/1 ratio at 40% and a 3/2 ratio at 80%, successful results were observed.
Additional Insights
The "New dot distribution" option also alters the 3/1 and 3/2 ratios, utilizing optimized presets established during the machine setup.
The Draft and Quality resolutions were deemed satisfactory as is, meaning overriding with the 3/1 and 3/2 parameters remains relevant in this context. For other resolutions, however, the "New dot distribution" option should suffice without further adjustments.