Digital BW, The Print

>...it appears that inks require typically 
> two different kinds of surfactant. ...

Surfactants differ in the extent to which they form miscelles or 
monolayers -- that turn into bi-layers on some surfaces like inkjet 
nozzles.  Some are hybrids.  Which characteristic one goes for 
affects how the ink responds in different situations.  It's one of 
the variables that we may be able to "tune" for different papers and 
inkjets.  So, if one has 2 surfactants with differetn HLB values (a 
measure of this characteristic), their ratios may be able to swing 
from one end of the scale to the other.

See http://en.wikipedia.org/wiki/Micelles for a visual of these 
structures.

I -- for sure -- have not sorted out all the variables and effects of 
these characteristics, but this is definitely one of the variables 
that could affect, for example, your desire to hold bleed on un-
coated papers to a minimum.  What is optimal for the nozzle may not 
be optimal for the paper fibers and wicking of the ink out on that 
fiber.  The ability to tailor inks for different combinations of head 
technology and paper is one thing that may be accessible to us.



Paul
www.PaulRoark.com