Digital BW, The Print

Last week I got my replacement 1280 for my first one. Figured I would 
give the VM inks another shot. Posterization is still there, 
horizontal banding is still there. I've tried cleaning, nozzle checks 
(never a clog), head alignments, nothing changed. Also ran through 
about 5 different sets of curves with the same results. Tweaking some 
sets got me almost there, but every time I messed with one part it 
would throw another out of whack. 

Out of all the curves I've tried for the 1280+VM set, the curves that 
got me closest to anything acceptable was the UT curves for the 1280. 

Thinking I might have another problematic printer, I try some Epson 
inks. Banding and posterization is gone. I've read a few places that 
mentioned something about the MIS cartridges maybe sitting slightly 
different in the carriage to cause some of these problems. Has anyone 
ever heard about this? I was looking to maybe tryout the UT inks, but 
I don't know if anything would changed compared with the VM inks. 
Anyone get bad results from VM inks that going to UT inks cured? 
Thanks, time to go pull more hair out.

matt