Digital BW, The Print

Eric,

>...
>Paul, you seem concerned about the fading of the small amount of 
>color ink.  Have you seen data that the colors fade unevenly? How fast? 

All the pigments fade at different rates.  Compare the RIT fade test results
relating to the MIS "archival" set (ignore the black, which had dye in it)
with fade test data on Claria on page 2 of this pdf:
http://www.epson.co.jp/e/newsroom/tech_news/tnl0611single.pdf

The substances and relative fade rates have not changed much.  Among the
color pigments, cyan is very lightfast and yellow fades the fastest.  The
pure MIS carbon routinely beats the neutralized inksets.

In a fade test with MIS inks in a 2400, the ABW mode was compared to a print
made with a rip that had no excess color in it.  At a point that would be
about equal to 13 Wilhelm years, the ABW mode print Lab L had increased
(indicating fading) about 36% more than the IJC print.

The tone shift issue is more complex, because it appears to depend on the
paper.  In general, it appeared that on EEM the yellow fading actually
lowered the tone shift of ABW mode prints, whereas on non-OBA, acid free
paper the yellow fade resulted in the print cooling down.  (I have not done
enough testing to know if the EEM yellowing of the 50% test strip patch is
due to the OBAs, acidity, or other factors.) 

Paul
www.PaulRoark.com