Digital BW, The Print

Hi Everyone;

I have been making digital BW prints for over a year now and have hit
somewhat of a brick wall.

1/2 of my photographs are of landscapes and building. These images with
sharp lines and distinct textures print quite beautiful and problem free
using my Epson 1280 , MIS VM inks and Paul's curves.

The other 1/2 of my images are of portraits and nudes. These are much
more problematic in their printing. It seems that images that are soft
in focus in some areas or have very delicate wondering tonal transitions
are quite prone to posterization.  It is almost like when the piezo
heads have detail to print the do really well but when there is not much
detail to hold on to things go haywire.

I am following all the well established procedures of good imaging. I am
scanning well exposed medium format tmax-100 in 16 bit and an agfa
T2500. My scans are so good that they require very little curve changes
before printing. My histograms look good.

I am wondering at this point if it is one of two things that is causing
posterization on some of my images. (1) could it be that the set of
Paul's curves that I am using are just not fine tuned enough to work for
some images with my setup. Would switching to a professional RIP such as
ImagePrint or the Piezography Plugin and other inks allow me so print
these softer images without posterization? Have users of these RIPs
noticed a reduction in posterization problems?
 
(2) Could it be that the Piezo technology is just not capable of
printing these kinds of softer focus grayscale images with out some
posterization? Has anyone out there been able to print such images successfully??

Any input would be greatly appreciated!

-Jeff Magidson