Digital BW, The Print

Hi. I am a fine-art black and white printer in Milan where I have a
lab where I want to start printing with an ink jet printer with carbon
inks for my clients (fashion, architecture, reportage, art photograpers). 

My problem is micro-banding. This is what I use: Epson Stylus Pro 7000
plotter; Mis Ultratone inks; samples of different papers (Epson
Enhanced Matte, Arches, Hanhemuhle Photo Rag). I have followed the
instructions in the Mis web site for the cleaning procedure with the
Mis cleaning cartridge set, I have installed the ink cartridges and
started the Epson purging procedure. After four tests, when I printed
the purging test pattern, I have micro-banding only on the full black
part. I have done the Epson software procedure for re-alignement and
nozzle cleaning and the problem remains. Now, I have no more ink and,
in order not to waste to much money in tests, I am thinking about
buying continuous flow inks. I am a bit disappointed. Before buying
these inks, I would like to ask you where the problem can be. In the
paper? In the inks? In the plotter hardware? 

Thanks a lot for your help. 

Gianni