Thanks for the reply, I have tried everything for the vertical banding and nothing helps, especially on Greens and Purples. In fact I contacted HP and got a letter stating that it is a known issue an there was no fix, but to try the same things you listed, heat and airflow settings, wish that was in the brochure. The color shift I was mentioning was when we printed 250 posters of 1 image on one roll of media. When the posters were trimmed and in a stack, I fanned through them and there was color drift throughout the run. Oh and I forget another issue, if someone is handling the prints and they touch it with a finger nail the ink scratches.