Digital BW, The Print

I have been using C86 with MIS EZN/EZW inks for some time now and am very happy with the 
output quality from this simple setup. 

I just think that the C86 printhead could be more stable. Even if I have maked several perfect 
prints, when I start the printer next day some of the print nozzles could be blocked.

And cleaning the printhead only makes things worse with the C86 is my opinion.

Another serious problem is that the black cartridge (i use the high capacity cart) suddenly can 
start to drip ink on the paper surface.
I have seen this problem with 2 black carts now.

Anyone who has the same experience with C86 and knows how to solve the problems??