Digital BW, The Print

Greetings-

I'm disappointed at the appearance of the "posterization" look on images that seem to 
have decent histograms (no severe cliffs). When a deep black meets a middle tone an 
unsightly separation occurs.

I've been following Roark's suggested media settings for Curves Adjustment layers 
using Epson 1280, UT2, Eboni Black, Macintosh 10.2.8 Epson Driver, and "Photo 
Paper" media setting. 

What are the implications for the driver's Media Setting on the above issue?

Any suggestion(s)  welcomed!

Thanks,
Robert Burget