Digital BW, The Print

David,

>> ...But, I've noted regularly that for those who do not use sepia, 
>> that spot has other uses -- another light carbon for better 
>> lightfastness...

>How does another light carbon == better lightfastness? 

The sepia ink is the weakest of the MIS UT inks, the pure carbon is the
strongest.  So, by taking out the sepia and putting in carbon, the prints
with the sliders (which use all the inks) will have less of the weak color
pigments in them.  For those who use curves, the cool through medium warm
prints will not be affected.

The neutral MIS inks now use a combination of carbon + cyan & R800 Blue
clone pigs that are very good, but probably still not up to carbon
lightfastness.  All of these inks are also predominantly carbon.

The sepia, however, even though I've removed the troublesome magenta and
substituted the R800 clone red, still has yellow in it.  Yellow is now the
weakest of the bunch.

In general, the more carbon and the less color pigs, the more lightfast the
image will be.

Paul
www.PaulRoark.com