Color Variation

Hello:
We are experiencing a color variation issue. When printing large coverage areas on CIS material the background color is changing from retain to retain. The color also appears to be uneven across the sheet. Both visually and in density. We have confirmed that most of the process variables and ink chemistry are functioning within target parameters. Do you have any suggestions on what might be causing this phenomenon and if so what can we do to prevent it?

Thank you

 

Sounds like ghosting are oscillating rollers on do you have corect roller settings
i used use my copper mcinley roller on tough coverage jobs on my 4o inch roland it helped.