Digital BW, The Print

Ernst Dinkla <edinkla@...> wrote:

> On 05/29/2011 05:32 PM, Paul wrote:
> > I've found the 2:1 dilution of HP PK with MIS glop 
> > (33% PK, 67% Glop) at 100% with QTR has a higher dmax 
> > than the 100% HP PK, no bronzing,...
> >

 
> ... If price is also considered then the HP 
> (diluted PK) quad becomes even cheaper than the Claria quad. 

> But printing on matt papers is not delivering a decent 
> black with PK. So less versatile.

The dyes on matte are not much to brag about. I see dye's advantages limited to glossy with the 2 exceptions I know of that hit very high dmax -- Photo Rag and a Red River matte paper.  Photo Rag prints too greenish with the 13% magenta blend (and I no longer have the full 26% magenta loaded), so the Red River is it for my matte printing recommendations.  Dyes are for high gloss cards & brochures only for me.  This HP-Glop combo is much more flexible -- better for display and not quite as dramatic for cards.

I'd plan on using Eboni MK with the HP PK/Glop inks.  The 7800 is, for example, headed for a "Dual Quad" - Eb-4 & HP/GO (the exact densities not as clear as I thought now).  But, Eboni will be there for the MK.


> For duplex printing, book creation, I guess the Claria 
> solution delivers less issues when pages are in contact with one 
> another. Any thoughts on that?

I think you're right.  I don't have that much experience with it.  The carbon pigment book makers have had some rub off issues.


> Is the effect of a higher Dmax by diluting the PK (even to 1:1) 
> plus a higher ink limit, not described with what a black dye 
> ink does, penetrating the coating deeper, not reflecting the 
> light at the surface and by that creating a better light trap? 

I'm not sure what all the factors are.  One pattern is that more dilute inks allow for a higher ink load.  I'm guessing this is, in part, a paper penetration issue.  The coating does appear to help the gloss, so that is probably also a factor.

It's interesting that we're apparently getting more black per pigment load also.  At 100% ink limit in QTR the 33% PK is blacker than the OEM 100% PK at 80% ink limit.  

The bottom line that is rather interesting is that with QTR or other rip, we might be able to fine tune the PK/Glop mix to optimize a paper-printer combo.  

The main thing I've been keeping my eye out for is an MIS Gloss Optimizer incompatibility with HP PK.  Usually reactions will take place quickly.  So far, I've seen no evidence of a problem.  

I'm hopeful that, with commercially available bottles, those so inclined will have some interesting flexibility here to improve the image as well as save money.  I like that combination of attributes.

Note that this ink in a hextone with Eboni-4 makes for more neutral matte printing even with the Epson driver that is, stability wise, second only to 100% carbon -- the best more neutral matte as far as I can tell.

>... I also wonder whether the changes you made to the Vivera PK 
> with GO have an effect on the fade resistance.

Obviously this approach has not been tested by Aardenburg-Imaging.  However, the use of glop as a cover on pigments seems to just slightly increase their fade resistance -- nothing dramatic, not as good as a spray.

Paul
www.PaulRoark.com