Digital BW, The Print

> ... As to sprays and uv varnishes, they are available in non-toxic 
>non-solvent forms now so that is no reason to avoid them.

The Premier Art "Eco" coating did well in Wilhelm's tests.  I have not found
the water-based sprays as easy to deal with, but they do now appear to have
an aerosol that might be worth trying.  

(Today I'm just slapping matte [Alpha, 16 x 20 Windmill and Granary] prints
into frames with no spray at all.)

Only in part OT, a friend had his 9600 UC color prints laminated, and they
look like Cibachromes.  In Gallery Los Olivos, that is what the somewhat
educated viewers seem to assume if they don't know what the actual process
is.  What surprised me is that the photographer (John Fitzpatrick) had the
laminating done at Kinkos, and while it is not my style, the prints look
really good.  


> ... As Paul's numbers about
> "carbon content" in ultrachrome pointed out from Epson's own data sheets,
> there is carbon and then there is carbon...

I think the bottom line is the fade test data.  I hope to have some results
in a month or so that will be indicative of some relative fade rates. 

There is also, of course, the question of how one defines "carbon" print, or
at what point the use of the term becomes, in effect, deceptive.  There have
been threads that suggest "ink" or "inkjet" should be in the name of the
prints most of us make, for example.  All of our inkjet "carbon pigment ink"
prints that are neutral have color pigments in them somewhere.  I've been
using a general approach that if the substance of the image is
"predominantly" carbon, then the label might be a useful description.  Few
things are 100% of anything.  

(In a previous life, I was involved with Federal rules that, for example,
with "down" products, allowed 20% feathers.)  In general, simplification can
have positive and negative results.  Search costs often limit markets.
Lowering search costs is often key to better market performance.  One can
argue that simplified labels can help with this issue.  (How one should
define actionable "deception" was central to untold hours of debate among
consumer protection types.)

Bob's numbers combined with the vagueness of how the MSDSs are worded
relating to LK and LLK composition, make it entirely possible that 2400
prints are close to being half carbon, even in the highlights.  If the fade
data do not show a material difference in relative performance, then the
issue is probably moot, in my view.

One can speculate about why Epson puts yellow in the mix, whether in
separate jets (like the 2400) or in the design of the LK particles
themselves.  (I wonder why the previous generation of UC LK had much less
relative carbon disclosed on the MSDS.)  

Frankly, I can think of several reasons to do this.  The most interesting
possibility is for lower Delta-E.  My old FSN ink mix achieved its relative
lack of "warming" by utilizing a counter-shift strategy based on yellow dye
+ cyan pigments that were added to achieve a counter-color shift that would
offset the inherent color shift of the inks that, otherwise, was very
visible.  Carbon does still yellow.  I have wondered here and elsewhere
whether it would be useful to implement a yellow-pigment-based counter-shift
strategy in the UT inks.  But, for the UT inksets, I have opted for
relatively higher fade resistance and just letting the carbon warm.  I think
the color shifts are consistent with traditional expectations and not too
significant.  

I have, however, noted that in a previous test, one version of a UC-based
UT7 appeared to achieved the best delta-e, while giving up bit of
performance in the density fade numbers.

Paul
www.PaulRoark.com