Digital BW, The Print

"Tyler Boley" <tyler@...> wrote:
>
> "dlruckus" <dlruckus@> wrote:
> ...
> > They do use color pigments to neutralize the shades...
> 
> very interesting Duane, I think there's been the impression 
> that they don't.

I detected evidence that HP's neutral inks were blended and posted it in December.  See http://tech.groups.yahoo.com/group/DigitalBlackandWhiteThePrint/message/94586  

The MSDSs and patents are consistent with this.

The potential differences are that HP put a substantial amount of resources into matching the fade rates of the color pigments as well as the electrostatic and other characteristics of the pigment particles such that they do not have the tendency to separate -- or so goes the claims.

The initial fade testing I'd done as of December was not sufficient to say how well the HP inks will do comparded to others.  I kept that fade test going for longer and stopped it when I became convinced the HP inks were at least good enough to continue to put effort into.  None of the inks tested at that point showed any Lab L change (i.e., it was below my ability to measure).  The HP did end up color shifting less -- less even than the 100% Eboni, which actually became slightly cooler, presumeably because the "other" stuff in the inks was burning off.

One comment here left the impression that the HP inks may use cheaper pigments, using the "even fading" as the cover.  I'd phrase this another way.  Using the very best color pigments may not be justified if they cause the ink to color shift.  For example, if there is a super cyan that is stronger than any magenta, it makes no sense to pay more for the super cyan and end up with an inkset that green-shifts.  So, it is rational to save that money.

My conclusion is still that we want the most good carbon, but the best blended inksets might be at a point where the substrate may be the weak link in typical indoor display.  So far, I remain impressed with the HP Z3100 PK, including the diluted versions.  There have been no clogs or other issues at all with the inks in my 1400 "NC2" setup.  See http://www.paulroark.com/BW-Info/1400-NC2.pdf

Paul
www.PaulRoark.com