QTR-Quadtone RIP

hi all:

i downloaded the QuadRIP drivers and am trying to get some decent prints using my 
existing Epson UC inks.  i'm also considering trying the NK7 ink for my fine art printing.  
my image is a straight grey scale image with Gray Gamma 2.2 profile and i'm printing 
using Photoshop CS on a Mac running OS X 10.4.8.  in the print with preview dialog, I set 
the source space to: Document: Gray Gamma 2.2.  the print space is set to Profile: GTR-
Gray Matte Paper, Intent: Preceptual, and use black point compensation.  

in the QuadTone RIP page of the print dialog, i've got Curves 1 & 2 set to UC_EEnhMatte-
cool and the tone blend set to 50/50 (the -black version of the curves seem to print too 
warm).  when i print, i get some nasty posterization that shows pretty harsh transitions 
between gray levels.  this is quite disappointing, since i had high hopes for this.  if there is 
something i'm doing wrong, i hope that someone could point out my mistakes.

i guess my question is, is anyone else seeing this kind of posterization?  i did a nozzle 
check and every color is printing solid lines.  is this posterization a result of the available 
colors in the Epson UC inks?  should i expect superior results with jon cone's NK7 inks?  i 
really want beautiful neutral prints from a selection of fine art papers and keep getting 
something that's too much closer to sepia with the epson inks.

thanks,
scott

Hi Scott,

 I had this posterization with QTR and Epson r1800 also, but changing to 
2880 dpi from 1440 changed a lot. There were still some banding, but not 
so bad that it could be seen in normal prints. Some posts I've read said 
that the Gutenprint (on which QTR is based) is not so good printing 
solid greys and suggested setting a narrow border in the image and 
adding noise there. Look at the archives for more info. I've printed 
with 2880 dpi really nice prints. The first time I tried QTR was also 
bit disappointing, I printed a test image, which had large smooth, 
gradually darkening sky, and the posterization was enoung to ruin the 
print. Then I forgot QTR for some time, and tried to get neutral prints 
with epson driver, but with no luck. Then I decided to give QTR another 
try, and set 2880 dpi, and voil\ufffd, the prints come out very good. Now if 
someone with  skills, could make new profiles for r1800, it would be 
splended.

best
-matti