Digital BW, The Print

John,

>I am setting up an Epson 7000 with Piezzotone selenium inks 
>and see that the inkset contains 4 inks. What do I do with the 
>two other channels? Surely something has to be in 
>there to keep the heads from drying out. 

It depends on which software you're using.  The old Peizo (R9) driver put
the same density in the light as dark ink positions.   

The new Piezo ICC approach has the following ink positions: 

New C = old C,
New LC = old M,
New M = old M,
New LM = Y, &
New Y = old Y.

>In the future I would like to try using a sepia cart in one of 
>them if possible.

>... using QTR ...

QTR may be the way to go given what you seem to want to do.

You may find the PiezoTone "sepia" is more like the MIS UT2/7 carbon tone.

Paul
www.PaulRoark.com 

For UT2 & UT7 information, curves, and settings see:
http://home1.gte.net/res09aij/