Thelo, it's looking like the GE/gray head has to be the villain. Software uninstall/reinstall
didn't work. Cleaning the printer manually didn't work (although it was a good
idea, quite a lot of ink to remove that probably would have caused trouble
before long). Had the printer do a head cleaning on the suspect set, then made a
print right away that was clean. Let the printer sit for six hours, then did a
print with GE whole sheet, .25" border, and the dark edge was back, where only
GE should be, fainter but broader, fading out over an inch or so. It sure looks
like slow seepage of gray ink into the GE supply in the head.
Just now, nearly 24 hours after that print with the machine idle, I loaded up
some heavy matte art paper and made a fairly substantial print (three-up 6.5x16
images) and it is perfect. I'm certain if it had been gloss medium the dark edge
would have been there. My new print head seems to be moving from Brooklyn to
Connecticut by way of Cleveland so I won't be able to install it and get a
certain answer until Monday at the earliest. But I'm finally optimistic we've
got an answer.---Carl