Digital BW, The Print

hi all,

i've been playing around with different prints using both the Clayton 
BO workflow, and Rorak workflow using the curves etc. for Ultra Tone,
i just got my 1280 - and after some initial figuring out - the printing 
is pretty smooth - and am getting nice prints -

So, I played around with both BO, and using the full ultra tone inkset 
- and I kinda like BO - and ultra tone gives very good prints as 
well...
it seems that each has its strengths, and depends on what you wanna get 
out of the prints... i like the feel i get from BO... i'm gonna show 
off some of my
prints to some friends of mine tomorrow.. and see what they think... i 
did show off some of them yesterday, and got good reviews...

one thing I've noticed with BO - is that in one of the prints there are 
some kind of horizontal lines ... i'm not sure if this is what is 
called "banding" ...
(am too new to know all the terms used here... :-)) however, when i use 
the full inkset - those lines go away - and the area is smooth... these 
lines
are showing up in areas of the shot where is there is a lot of sky... 
(evening sky)... and appear to be located in one particular area of the 
print...

probably it has to do with the image itself, rather than the printer... 
but i'm wondering, why this would show up in BO, and not when using the 
full inkset?

thanx

Altaf