Digital BW, The Print

Hello Paul,

  please, excuse my late reply. I have been quite busy lately.

Thanks for your long post. Most of your points are well thought.
One of them is crucial and  I have, indeed, overlooked in my considerations: with a RIP you can appropriately limit the ink load of a particular channel which, as you noticed, is extremely important for uncoated papers. Too much ink and rendition of the print is very ugly (we have learnt that at the beginning of our journey). We observed that with Epson variable droplet printers (basically, all the post 7500 printers) if you exceed an ink limit of about 50%, the droplet is too big for an uncoated paper. Therefore, we formulated the ink dilutions accordingly. I am not sure how to control the ink limit with the HP OEM driver. That's why I believe R&D with a new system would require a coordinate effort by several people interested, unless one has large disposable time.

Regarding the clogging, we noticed that it occurred most frequently in the lightest dilution (1% in our case). A quick check shown that the Ph was off the recommended range for this dilution. After appropriate correction, we did not have any more clogging for this head in about six months. The autoprint program  requires that you have the roll paper loaded and exchanging paper every time you print.  However, upon you suggestion, we will try this option. We did not had a failed head in two years. But, to my understanding, quartz is sensitive to acidic substances and I am afraid that an ink with the wrong Ph would shorten the life of the head. That's why a user replaceable head would be a better insurance.

Regarding Epson dithering with QTR, if you look closely, it is quite noticeable. Both HP and Epson OEM do better in that respect. It is a minor effect for me, as I use 35mm silver negative and the grain gives larger contribution than dithering (I have purchased a DSRL and tested extensively; now it seats in a cabinet as I just cannot get along with the plastic look of the results). In any case, I would be happy with a better dithering.

Finally, I am not surprised by the fact that diluting an existing black ink in order to match the viscosity would give sub-par results. That's why I believe making an ink from scratch with the Eboni pigment dispersion could be a better starting point.

I will keep posted with this R&D.

Ciao,

  Mantinieri

P.S. I have read the article on your work on Rangefinder magazine and liked very much, as well as your photos.