Digital BW, The Print

I'm using a couple of modified UT2 inksets; in one of them I've 
changed the sepia in the yellow position for FSN-y, and I've changed 
the Eboni for PKN; in the other set I've left Eboni in place and 
changed the sepia for FS-y.

question: which inks constitute a pure carbon print, is it just the 
use of Eboni, PKN, M, LM and FSN-y or FS-y; or just the use of Eboni, 
M or LM,

Jamie