Digital BW, The Print

This is a preview of my latest effort at an inkset for B&W printing.  It is
an evolution of the UT7 inkset, with a new cool toner and the sepia replaced
by a toner that lies on the Lab a* axis (with Photo Rag and Ultra Smooth at
L 50).  So, we have a true, if minimalist, "color" space - perhaps better
called a minimalist gray space.  I've posted "picture" of the space at L 50
on Photo Rag at http://home1.gte.net/res09aij/UT6_Space_PR.jpg

 

The inkset is mostly carbon and uses only MIS Cyan and R800 Blue for the
colors - no magenta or yellow.  The toners are blended color and carbon and,
on Photo Rag, have a chroma that is actually less than the carbon.  So,
we're talking about an extremely low gamut.

 

The inkset prints neutral on EEM and Kirkland with no curves and the Driver
Color Controls set to 0.

 

ICCs or curves can control the inkset tones on any paper.  I plan on using
ICCs for the obvious advantages those offer.

 

For large format printers, Eboni matte black can be loaded and the black for
glossy papers can be generated by the 2 dark gray inks.  So, this will print
on glossy or matte papers without the need to change inks.

 

With RGB curves embedded into ICCs with Roy's Create ICC software, I've been
able to have the program linearize curves that have only one or 2 points on
each curve.

 

The procedure for making curves is very simplified.  With a
spectrophotometer, one can usually simply set the Lab b* axis and
approximate 50% density with the C and M inks, which are the same density
and can thus control the b* axis with offsetting moves.  Then just pull the
tone out as far as wanted on the a* axis with the Y ink.   Print a 21-step
and let Create ICC do the rest.   Of course, how long this actually takes
depends on how much or a perfectionist one is.

 

Where exactly the C, M, & Y ink points are in the space depends on paper and
density.  So, the Y ink is not always exactly on the a* axis.  However, on
most papers the setting of the a* value has only minimal impact on the
already set b* value.  Having the inks laid out in a basic Lab format
greatly simplifies the control of this inkset.

 

The inkset is now running on my R220, but I'll port it to the K2 printers
ASAP.  They are one of the main targets.

 

This is a work in progress, but it's up and running and looks like a
significant step forward to me.  It'll give us almost total control of the
near-neutral space in B&W prints - with any paper.

 

Let me know if you have any suggestions for needed features.

 

Paul

www.PaulRoark.com <http://www.paulroark.com/>  

 

 

 



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