Digital BW, The Print

I have had a slightly different experience.
I bought a brand new printer, never run anything in it, and a set of 
MIS GP colour inks (uses Eboni as the black)

The black clogged, and clogged and I never, once, got a good print 
(the colours printed fine).  I switched to PK black and it was great, 
but I didn't like the bronzing effect on non-matt paper (plus the 
known low Dmax on matt was no compromise) and couldn't afford 
Pictorio film on a day-to-day basis.  Therefore I switched back to 
Gen4 black, got a custom profile made (the MIS canned ones are 
ABSOLUTELY hopeless) and am getting superb prints. No clogs.

I had my other 1290 running the old VM hex set.  I switched to the 
Ultratones, and was unlucky to get the bad batch on inks.  However, 
even with a new CIS cart, the black just clogged and clogged and 
clogged - and you guessed it, I never got ONE good print.

Switched to GEN4 and the original VMs, working like a dream, despite 
a glitch with a bad CFS cart to start with.

I am one guy in a big pond, but I will never go near Eboni black 
again - too many grey hairs, burst blood vessels and ruined sheets of 
paper / CFS carts for me!

Good luck

Steve