Digital BW, The Print

> What is meant by the term "carbon core"?
> 

The short answer is that the B&W images I'm printing are mostly composed of
multiple carbon inks -- K, LK, and LLK.  So, achieving the best partitioning
of these core inks is a critical first step in the way I profile the B&W
inksets I'm currently using.  

To elaborate (i.e., the long version is ... ) in my view, and I think it is
fairly widely held, the best current B&W inkjet prints are those that have
mostly carbon (or equally stable, neutral pigments) as the image-forming
substance.  Carbon is warm, so we use color pigments to make a neutral image
-- or other tone like sepia.  We either mix that into blended inksets, or we
blend the carbon and color pigments on the paper via the printer, driver,
and software profile.

With the Epson K3 inkset and the variable tone inksets I've designed, one
"channel" is pure carbon -- no color pigments added.

With the older printers, with large dots, I had to do several things to
increase smoothness -- blend the colors with carbon to reduce their gamut
and limit the number of toners. 

With modern Epson printers, we can achieve the smoothness we need with
non-blended, generic color inks (LC, LM, & Y) and standard carbon inks (K,
LK, and LLK).  This is much of what the Epson "K3" approach does.

What I'm doing now is using that same basic approach, but in a generic way
and with QTR.  This, hopefully, will give us a powerful, simple,
transportable, general and generic B&W workflow from the basic entry level
hextone printer to the 3800 and beyond.  It's now working very well on my
220 (and 2200 and 7500 in different variants).

The starting place, I believe is to have the best partitioning of the core
of this image and system -- the K, LK, and LLK inks.  These will then form
the core of all the various tones.

Once we have a straight-line carbon core, the toners can be applied to that
same core as close to straight line "curves."  So little of the toners is
needed, being pure color, that the toned images are not that far from linear
and are easily linearized in the final profile.

The sliders in the driver will be able to shift the toner mix around the
same straight carbon core.  So, we're looking at a space with a carbon core,
and slider controls -- 3 profiles with midtone, highlight and shadows
sliders.  My experience so far is that a straight, uniform carbon core makes
this slider-accessible B&W space work best.

The carbon core description will be in each profile Point List and open for
all.

Paul
www.PaulRoark.com