Digital BW, The Print

> Don't worry about hijacking the thread.  It's all interesting.  The 
> approach is much wider than the 1800 and Eboni. 
> 
> One thing to be sensitive to is potential incompatibilities.  I've 
> been told, for example, that the base I'm using for the Eboni-6 is 
> not compatible with some modern inksets -- Epson UltraChrome 
> included.  I may have experienced an un-characteristic nozzle clog 
> when I used Glop and Eboni-6 (older matte-style base) in the same 
> printer.
> 
> Paul        

Thanks for your understanding Paul, and yes I thing it's a wide issue.
Now one thing I don't fully understand is the multi-pass to lay down 
GO. At the Dmax point I understand but in other parts of the 
greyscale I feel you can process GO as an additional partition.

Say in a simplified example you have at a given output 25% dark ink 
and 75% light ink for a 100% coverage. The light ink is 50% density 
of the dark one. At this specified level you need to apply 20% GO 
(empirically determined and that's probably a bigger issue). As you 
know there is not a single mix to deliver this output density : 25% 
dark and 75% light with light density at 50% dark density is 
equivalent to 62.5% dark alone. If you have to limit total light and 
dark coverage to 80% to allow 20% GO and full 100% coverage then you 
can output 35% light and 45% dark (same 62.5% dark equivalent) 
together with the 20% GO. That trades GO against granularity but it's 
a single pass.
Correct ?

Olivier