Digital BW, The Print

While this is a B/W group I have seen some have tested and discussed 
Colorbase.

I have been trying to run it with mixed results. I run it with a 
Pulse spectro and custom-profiles made with the same package.

On USFA I got fairly good results and no issue (that I can 
identify...). 

Oppositely on Archival Matte with the proper driver settings the 
results are below expectations not to say puzzling. With CB not 
activated and a custom profile with no clb, the print is pretty good. 
With CB clb file activated and a custom profile made with clb 
activated the result is poor : on a portrait I often use for profile 
assessment, the skin is reddish and bluish. At visualising the 
profiles, the one made with no clb looks smooth evenly distributed. 
Oppositely the one made with the clb file shows a very strange "leg" 
at about L* 20-25 in the +a-b area. I have processed (re-print, re-
mesured) the target(s) many times also having the same profile and 
the same output. Of course the output does not match the screen 
softproof (2070SB Optix-profiled). This +a-b "leg" is very puzzling : 
I have never identified it in the past on a 1800 (but it uses another 
ink set) and it does not exist without clb activated.

One major drawback I find in CB is that there is no way (that I've 
found so far) to visualise the measurement of the clb print target 
oppositely to profile visualisations that are widely available(no 
delta, no graph... nothing). From the Pulse experience, I have often 
come across wrong measurement that are not explainable. But at least 
one can delete and re-process knowing the profiling has failed. This 
being said, various measurements, and profile creations come to the 
same "bad" result.

So questions :
- Has anyone came across the same situation (CB activate, cutom 
profile with the clb, Archival Matte-EEM) of a aditional gamut in the 
shadow in the +a-b area.
- Has anyone found a way of assessing the clb files.

PS : to Steve Kale
I now suspect why Epson recommends not to cut USFA with the in-built 
cutter. The issue is not the thickness of the paper though it is very 
thick and getting the cutter dull soon. The issue is that the cut 
creates a lot of particules-dust...that the printer should not be too 
happy with. USFA is a nice paper, but the other thing one has to deal 
with, in case of roll-cutting, is the curl of the paper : it is 
simply aweful. I have not yet find a way to deal with it without 
damaging the surface of the paper which extremely fragile.

Olivier