Digital BW, The Print

Clayton, 

...

> The blackest possible print area can only be achieved when there is
> 100% coverage by only the K ink.

With a rip I can get a better dmax with cyan added to the black.  The Epson
driver can't do this, and the old printers that under-print the black ended
up with a lower dmax.


> Many systems that blend inks often
> mix something else along with the K, even in the lowest zones.  This
> effectively reduces the dmax.

Usually, but not always.  The UC MK with UC cyan added is the most dramatic
exception I've seen.   With UT7, a little dark cool gray added to the Eboni
can also increase dmax a bit. 


>  I see this with UT7 using sliders, where it can't match BO dmax.

The UT7 sliders do not underprint the 100% black with gray inks.

I just printed 100% black patches with UT7, Eboni, 2200, and EEM.  With the
sliders the dmax is 1.66.  With black only the dmax is 1.66.  There is no
difference.

What we've discussed in the past is that the various approaches differ with
respect to how much contrast exists between 100% and 95%.  With curves, this
is totally controllable.  With the sliders, there is less flexibility.  The
image has to be adjusted in Photoshop to fit the printing characteristics --
which is true in any case.

Paul
www.PaulRoark.com