Digital BW, The Print

Paul, A bit more info regarding this from Epson. The latest patent
data(oct/nov 08) show them using both acid and base buffers to
maintain pH levels to a declared optimal level between 7 and 8.5 for
very recent inks. The acidic buffer can also be a number of things but
one mentioned is citric acid, another old photographic standby.
Also mentioned is the reason for the pH range. Apparently the print
head coatings can be disassociated and jets damaged by levels below
and above the stated range while all is well within that range.

As an aside, the EDTA listed in regard to the Tilex product also turns
out to be a low level ingredient in a number of their ink formulations
so is unlikely to be a problem so long as a mix is within above pH limits.

Regards
Duane




--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "pr_roark"
<pr_roark@...> wrote:
>
> 
> My reading indicates that electrostatically stabilized pigment
> dispersion approaches are pH sensitive.