Digital BW, The Print

So far a lot of black inks have passed the discussion on what delivers the
best density reading and stays there when exposed to light. On the 9000 list
some people have observed that Indelible pigment black has a higher density
(eye measurements AFAIK) than Ultrachrome and Generations 4 Enh. black. I
have no personal experience and no knowledge of the Indelible black ink. Not
whether it is pure pigment either.
Anyone observed that high density too ?

Ernst