Boudica nailed it. Just went through this myself last week. "under-performing" box of Magenta. In my conversation with HP they made a good point....look closely at your prime bars. "under-performing" ink will jet weak at the leading/trailing edges. Very similar to the older scitex line that used to experience weak center jetting (which was generally a bad head on those machines), but in this case it's the opposite, weak edge jetting as opposed to the center being weak. Weak edge jetting is a sign of "under-performing" ink. At first glance my prime bars appeared perfect but upon closer inspection I was getting weak edge jetting and it turned out to be a bad, excuse me, an "under-performing" Magenta cartridge. Also shake your cartridges, HP suggested shaking weekly on Monday morning, but we are going a step further and shaking every morning. So far so good. Hope it helps!
