you mean banding?
i think i can see what you're talking about in the photo.... dark lines in the head-scan direction of your print?
what does your test print look like? (deflected nozzles/ink starvation could cause banding)
does this happen on all media or just the one in the photo? (if the latter, then you have media feed compensation issues)
does this happen on all files run or just that one in particular? (if the latter, then you have gradient saving/handling issues)