Digital BW, The Print

Roy,

I saw the spreadsheet - seems like some midtones went adrift between the 
cool and the warm. Yeah... separating color from density will be the next 
challenge in designing monochrome drivers. 

As for my sepia curves - they are sooo sepia that metamerism doesn't have a 
chance to enter the equation.  IOW the gray is so flooded in yellow orange that 
a slight shift wouldn't turn it green or magenta. The problem seems to be 
when you are trying to hold neutrals out of primaries. In my case, I base the 
scale on the grays and then start "pumping" yellow and L. magenta reducing 
gray desnity just enough  to compensate (mostly for the density of the 
magenta plus whatever the densitometer makes of the yellow under its 
"visual" setting - which is a whole other  can of worms).

As for your load order with the 2200: I agree except for loading the two blacks 
at the same time. Seems like a waist of a position since these carts are so 
easily changed back and forth (unless you use a CIS). But otherwise, yes: we 
only really need an extra light gray to get a full grayscale, the equal of a 
dedicated bw printer. Beyond that, its tone city!

The only theoretical reservation is whether toning by adding dots of primaries 
is inferior to using toned gray inks (i.e. sepia. cool etc). Both on account of 
permanence and visually where the eye has to synthesize the dots (e.g. 
highlights). 

But, as I said.... these are theoretical issues. I am currently getting a beautiful 
chocolate warm print with "golden" highlights by a 50:50 blend of a neutral 
and a sepia profile and then hitting the whole thing with a 5% tint of the sepia 
"tinting profile". The tint is masked to preserve the highlights.


Antonis








> Antonis,
> 
> I enjoyed your description of the IJC linearization and the issues found.
> I don't own a 2200 but Carl Schofield has done some work on the curves
> for it using QuadToneRIP.  During that, we also ran into the issues of 
> adding light-cyan and light-magenta to neutralize the tone.  In fact I think
> trying to compensate for the added density was the major effort in the
> cool curve.  Carl also had some nice plots of density. See:
> 
> http://harrington.com/QTR-2200.pdf
> 
> I see you did some sepia curves lately, did you notice much metamerism
> in those prints?   All along the yellow ink seems to have been blamed
> for metamerism -- I wonder how true that is.
> 
> Roy