I run PosterJet RIP software to print to an HP DesignJet z2100. The issue I have is that I am trying to print a file that has a background with a Black only gradient in it and a color photo in the foreground. When I print it out, the RIP adds a "rich" gradient to the background, so that it now looks maroon instead of pure gray. Is there a way to preserve the gray only gradient for the background?