[What they don't tell you is that the Hahnemuhle, instead of fading away quickly once it has crossed the e
Most of the green shift is occurring in the darker mid tones not high values that would be from any oba in Photorag.
That's the second component of the fading - the progressive deterioration of the coloured toning pigments.
Piezography's non-pure-carbon inksets are toned with Conecolor inks, which have poor permanence compared even with Epson's Ultrachrome K3 inkset.
But look at the progression of colour shift on both papers over time. In both cases, the L* value doesn't change much - the carbon component isn't going to fade. The I* colour, though, drops significantly in the first few tens of Mlux-hrs, then continues at a more gradual pace of decline. This occurs with both papers - just that the initial change is greater in the Hahnemuhle than in the Canson (at 40 Mlux-hours, the I*colour of the Hahnemuhle is 88.8 (average)/81.6 (worst), while that of the Canson is 93.2/91.4). Once the initial change has occurred, there is little difference in the rate of colour change between the two papers. At 100 Mlux-hrs, the Hahnemuhle scores 82.2/73.9, while the Canson scores 88.4/83.7 - in each case, a change of 5-6 (average) to 7-8 (worst) from the 40 Mlux-hr score. So, something is causing an initial, relatively rapid colour shift in both cases (more so in the Hahnemuhle than the Canson), but, once this shift has occurred, colour shift on both papers continues at about the same rate.
And look at the absolute a* values of both papers. Using 100 Mlux-hrs as an example, the inkset on the Hahnemuhle is actually
less green than the Canson, even after it undergoes greater colour shift. Not coincidentally, the difference in a* value seems to be about the same as the difference in a* value at 100 Mlux-hrs between the white point of the two papers - the a* value of the unprinted Hahnemuhle at 100 Mlux-hrs is 0.3 less green than the Canson, and the difference between the two printed papers seems to be about the same. So, despite the greater shift from the initial state, the Hahnemuhle is still less green after 100 Mlux-hrs - and, at that stage, both papers are shifting at about the same speed, after the Hahnemuhle's greater initial shift.
Yes you could do splits well with studio print in a blue toned dual quad set. I just have no interest in doing splits.
Nor do I, in most cases. But, if you have 10-12 ink channels available, you may as well use them...
It is certainly doable and will try it first on a smaller printer. You can use Vivera blue or Canon blue like Roark does with success. Problem is what percentage to use in each channel. But if I did get it right it could revolutionize my workflow.
It would certainly require a lot of experimentation. Maybe start from Roark's mixtures and take it from there (bearing in mind that Cone Carbon is warmer than the original Eboni inks he was working with, although the new Eboni inks are a lot warmer than the originals).
Right , problem is getting them ground to tolerances that fit through an inkjet nozzle. Grinding also changes the hue. If it were easy Epson would have done it long ago in place of those ugly green-brown carbon grays they use.
Grinding them small enough isn't really a problem. It changes the hue to an extent (you'll get some shift, but not to the extent of blacks or greens turning to reds or yellows, as with the smaller particles in plasmonic inks) but that barely matters if you're just trying to neutralise a warm ink, rather than develop a wide-gamut colour inkset.
I suspect the reason Epson hasn't done it is simply because it didn't matter to them - the greys are part of a colour inkset, not intended to be used in isolation, and any necessary toning can come from the colour inks being used at the same time. Clearly HP took a different approach - their Vivera black/grey inks are meant to be used in isolation, so are neutral.
Don't need to do that Vivera inks are as permanent as piezo carbon and already neutralized . But no they don't work as thermal heads have a heat consideration and the chemistry is designed specifically for them. Though you apparently can get away with doing the opposite apparently - thermal inks in Epson printers. I'm trying to get away from Epson as fast as possible .
I suspected as such. Not sure if the resin coating can take the heat without gumming up. Although it may be worth experimenting with just before you're about to change a print head anyway.
I just went through some more of the Aardenburg results - it does actually seem like the Vivera black-and-white mode is just as lightfast as the Cone and Eboni pure carbon inks, with most of the colour shift attributable to changes in the underlying paper (in all cases the plain-paper patch seems to be among the worst-performing patches). I wonder what pigment the HP inks use to tone the black carbon - maybe it actually is a non-fading mineral pigment, as described earlier.
Maybe it would be possible to dilute down Vivera black and grey inks, to create a six- or seven-shade black-and-white inkset, that would be neutral in tone, nearly nonfading and could go in an HP printer. It could even go into the cheaper Z2100, since you wouldn't need nearly as many ink channels (MK, PK, gloss optimiser plus the greys). You'd just need a RIP to drive it.
It was also interesting to note that identical papers seemed to shift differently. Compare #148 with #141 - look at the 140 Mlux-hour results, which are the last ones for the HP test. They even measured significantly differently to begin with (#141 being bluer than #148, despite both being Hahnemuhle Photo Rag 308gsm). For whatever reason, the plain paper patch on #141 also scored an I*colour of 100 at 140 Mlux-hours, while #148 only scored 94.8, despite both having shifted in colour - neither patch would have had any ink on it, so I'm not sure of the reasoning there.
