Epson CW-8000 Print Quality Corrective Actions

1. Vertical Line Banding

Vertical banding in the paper feed direction. The vertical banding is more apparent when printing on high-gloss media and/or solid colors. With solid colors, the appearance will vary depending on color and/or pattern. The amount of vertical banding will vary.

Cause:
The printing density varies between the print head chip boundaries. The printing density of the print head chip boundary or overlap area is caused by a variation in nozzle discharge. It becomes more apparent when printing on high-gloss media.

Corrective Action:
The vertical banding can be minimized by performing the banding reduction adjustment. The adjustment can be performed via the Printer Driver or the Printer Setting Utility.

Driver:
The following only works from the Epson printer driver or applications that have the Epson driver built into the software

• BarTender
• NiceLabel
• CODESOFT
• Spectrum/LPS

1. Select the General tab
2. Select Advanced
3. Adjust the Banding Reduction slider to make the lines appear lighter or darker

Printer Setting Utility:
For applications that do not utilize the Epson printer driver, you can use the Printer Setting Utility.

1. Launch the Epson Printer Setting Utility
2. Select Print results adjustment
3. Adjust the Banding Reduction slider to make the lines appear lighter or darker

2. Uneven Horizontal Lines

Horizontal lines may appear due to a slight paper feed fluctuation by the gap area of the die cut labels when crossing over the feed rollers.

Cause:
The paper feed fluctuation is caused when the paper feed rollers change in speed when the paper feed rollers drop into the gap area of the die cut labels. This will occur with die-cut thicker mil label media, like synthetic or glossy labels, as the feed rollers pass over the gap area. This can cause a speed variation resulting in horizontal lines. This is more apparent with solid areas. The CW-C8000 has improved with the change of the paper feeding mechanism to minimize horizontal lines.

Corrective Action:
The horizontal lines can be improved by changing the following:

• Print using die-cut media with the matrix intact. This would help minimize any speed variation as it passes over the gap area.
• This would be equivalent to printing on continuous media.
• Use fewer solid patterns in the label design.

3. Misregistration/Ghosting

Misregistration is the inaccuracy of the dot placement.

Cause:
The speed fluctuations in the paper feed transportation will cause variability in the dot placement. The following are items that can cause misregistration:

• Rewinder
• Label media misrouted through the rewinder, specifically not using the tensioner roll.
• Media hold pressure may be too high for thinner label media, causing the label media to stall intermittently.

The CW-C8000 has been significantly improved by introducing a vacuum paper feed unit to mitigate paper feed fluctuations.

Corrective Action:
There may be instances where media pressure (vacuum) may need to be adjusted to improve misregistration. By default, the media pressure is set to auto and can change based on the environment and the type of label used. The change to the media pressure can be done via the driver. By checking the media pressure check box, it will be set to manual, and the amount of vacuum can be modified. The recommendation is to start at a level of 10 and test thereafter. The other recommendation when printing black solids and fonts is to design the label using RGB values for black content. The recommendation is to use RGB values of 0,0,0 for black. This ensures the driver will convert black to pure black and not have what appears to be misregistration.

Driver:

1. Change the media hold pressure setting in the driver.

• From the Main tab, select Advanced.
• Select the checkbox for Media Hold Pressure.
• Start at a setting of ten and test. Keep reducing the pressure by one until the results are acceptable.

• Enabling Edge Adjustment may help with reducing and/or eliminating white space between text and background color.

4. Star Wheel Marks

Star wheel marks appear as white dots on the label media.

Cause:

Star wheel marks occur when the star wheels are pressed against hard surface media types. High-gloss media types are more susceptible because the ink does not dry quickly enough. This is dependent on the media’s ability to absorb the ink correctly.
Corrective Action:

The CW-C8000 has improved by having fewer star wheels with the introduction of the vacuum paper feed unit. Due to the reduction in the number of star wheels, the star wheel tip load is reduced.

• Decreasing the print speed of the printer will allow the ink to dry a little longer.

• Try using different media.
• Clean the star wheel unit. (Disassembly required)

5. Irregular Solid Pattern

An irregular pattern, like wind marks when printing solids on glossy media.

Cause:

The irregular pattern can be caused by airflow around the print heads and media, causing dot placement to fluctuate. The CW-C8000 allows for the adjustment of the platen gap (Head-Media Clearance Height) for thicker media. If the platen gap is set to a thicker media setting when printing with standard media, it can cause the dot placement to fluctuate. The dot fluctuation is more susceptible to using glossy media.

Corrective Action:

• Ensure that the platen gap is set to normal using the Printer Setting Utility.

• Try using different media from the same or other manufacturers.
• Use fewer solid patterns in the label design.
• Enable slower print speed at 150mm/s

6. Rewinder Roller Marks

Roller marks on the printed surface of the label. Note: The picture has been enhanced to show the roller marks.

Cause:

Roller marks from the rewinder tensioner roll shaft are rubbing on the printed surface of the label that hasn’t dried completely. This is dependent on the media’s ability to absorb the ink correctly.

Corrective Action:

Consider the following changes:

• Clean the tensioner roller with alcohol.
• Try using different media from the same or other manufacturers.
• Use fewer solid patterns in the label design.
• Enable slower print speed at 150mm/s.