Digital BW, The Print

David;

>> I need the 
> random "grain"/pattern similar to an aquatint screen or bitmap 
image. 
> To get this I've been printing grayscale images using Quadtone RIP, 
> with matte black only ink, printing at 720 DPI, uni-directional.

Banding on transp. film is very common, more the rule than the 
exception. I think it has to do with decreased dot-gain. If you 
need 'grain', introduce it in the image with a grain filter, or 
PS's 'add noise' function, but print the neg at the highest res the 
printer will allow, (2880 and 'finest detail)and as many ink channels 
as you can muster.
> 
> I've also tried printing using the R2400 Advanced B/W mode, which 
> doesn' not give me options for resolution or ink cartridges, but 
I've 
> been having the same banding issues in this mode as well. 

In the long run I think you'll do better with PK, if only because it 
will stay on the film long enough to do the job? If you need more 
density, try the 'spectral density' approach, that is use the plate's 
lack of sensetivity to red to build the density to the level you 
need. I'm thinking QTR with two blended curves might give the best 
combination of number of channels firing, and density. One curve 
would be only the blacks: PK, LK, and LLK. The second curve would be 
M and LM, with perhaps yellow as a toner to produce red,if you really 
need heavy density, as for platinum printing. The two could be 
blended to suit. This would give you 5 or 6 channels firing, and 
might just do the trick

 
Hope some of this helps

Steve Karafyllakis