Permanence of non-carbon/sepia Piezography

[sanking]

I understand that the sepia/carbon Piezography ink set is the most permanent of the Piezography ink sets from inkjet.mall. And the Eboni-6 ink set from inksupply.com is also very permanent.

Two questions.

1. In terms of permanence how do the Epson UC and K3 inksets compare to the Piezography non sepia/carbon ink sets (selenium, warm neutral, etc.) when using QTR to make monochrome prints?

2. Piezography with sepia/carbon ink set seems much more popular than Eboni-6. Is this because the results are superior, or is it because Piezography is more of a plug and play system with the supplied K7 QTR profiles?

3. Could the Eboni-6 pigments, which cost a lot less than Piezography K7, be diluted to work with the K7 profiles supplied with QTR?

Thanks in advance for any comments.

Sandy

[Oren Grad]

1. In terms of permanence how do the Epson UC and K3 inksets compare to the Piezography non sepia/carbon ink sets (selenium, warm neutral, etc.) when using QTR to make monochrome prints?

The only publicly available data on the stability of Cone inksets that I'm aware of is that posted by Mark McCormick-Goodhart of Aardenburg Imaging. You can wade through the list here to find the Cone samples - look at the "Ink/colorant" column:

http://www.aardenburg-imaging.com/cgi-bin/mrk/_4899c2hvd19kb2NfbGlzdC80

You may need to register as a member to open the detailed reports for each; this is now free, though I'm sure Mark would appreciate a donation if you find value in his work.

[MHMG]

...You can wade through the list here to find the Cone samples - look at the "Ink/colorant" column:

http://www.aardenburg-imaging.com/cgi-bin/mrk/_4899c2hvd19kb2NfbGlzdC80

You may need to register as a member to open the detailed reports for each; this is now free, though I'm sure Mark would appreciate a donation if you find value in his work.

Or you can simply filter the list for [Ink/colorant][contains] "cone" to narrow the list down to all samples of piezography:)

As Oren noted, you will need to register and create a login/password, for free, to download the reports by clicking on the links in the "test report" column.

AaI&A members have been particularly interested in monochrome printing options, and I've received a lot of really cool samples from AaI&A members. You can also filter the list for [test type][contains] "B&W" if you want to narrow it down to only monochrome print samples in test.

The test results to date have been very informative. The Cone Carbon ink tests (formerly called Carbon Sepia and listed in the database that way) are indeed full carbon and responding with exceptional stability. However, the "neutral", "warm", "selenium", and "special K7" tints generally exhibit a subtle shift towards green (well, maybe not so subtle depending on your visual expectation for hue constancy) , probably due to loss of magenta colorant added to the carbon pigment perhaps along with some cyan colorant (C+M = blue) to cool the yellow (brown) tint of full carbon pigment. The OEM printer monochrome printing modes (e.g. Epson ABW, Canon grayscale mode, and HP grayscale mode) probably use similar colorant additions (some incorporated directly in the photo gray inks and some added during printing by other color channels) to achieve neutrality, but they apparently have a more stable magenta and thus are outperforming the Cone neutral and near neutral tints in terms of early stage light fade resistance.

The exposure doses that the more neutral Piezography ink sets can tolerate with little or no noticeable fade are generally falling in the 35-45 megalux hour range, although papers containing high OBA content can drop any B&W sample scores to less than 10 megalux hours. 40 megalux hours equates to only 20 years on continuous display at 450 lux for 12 hours per day (i.e., the Wilhelm Imaging Research assumed values for display time predictions, albeit WIR uses more liberal fading endpoints than AaI&A). However, knowledgeable collectors will display at far lower average light levels and for less daily illumination time, so it's not unreasonable to expect that prudent display conditions can achieve 100+ years of little or no noticeable light-induced fading for all piezography ink sets. My personal take on the AaI&A test results is that one should avoid high OBA content papers for all monochrome printing (OBA burnout pulls all the highlight tones more yellow especially when the inks are really stable!!) and also treat the more neutral Piezography monochrome prints similar to color chromogenic prints from a curatorial perspective. Fuji Crystal Archive II color paper gets an AaI&A Conservation display rating in the 18-30 megalux hour range. That said, it's important to also understand that while color prints will continue to fade at the same or increasing rate as higher exposures are reached, the Piezography neutral/near neutral tints will stall in fading as the color pigments burn out and the carbon remains. What this means is that the Piezography prints will not likely ever exhibit severe loss of information content like what happens to color prints as they reach severe levels of fade, but this attribute may only be of consequence to archivists while of small consolation to printmakers looking for high hue and chroma stability for the delicate tones and hues they've worked hard to coax into their prints.

I've learned a lot from the performance of the monochrome inkjet print samples in test at AaI&A, and I hope AaI&A members have, too. We've covered a lot of interesting ground with optical brighteners which you won't find elsewhere since most industry-sponsored test methods are not sensitive enough to pick up the OBA burnout. And the AaI&A database shows clear interactions between color pigment sets and the media, hence revealing that a good choice of paper for Epson inks is not necessarily the best choice for Canon or HP inks,and vice versa, etc. And the tests track non linear fade rates exceptionally well, enticing me to want to work on some dynamic comparative graphing of the results on the AaI&A website. All this said, I've grown weary of trying to find reasonable funding to keep the digital print research program going at AaI&A, and the number of hours needed to just keep up with the current samples in test, let alone adding new samples to the database, has now exceeded the volunteer hours I can devote to the program. I have a tough decision to make as we enter 2012, whether it's time to wind the program down or to keep going and hoping for funding that so far has been very ellusive.

kind regards,
Mark
http://www.aardenburg-imaging.com

[sanking]

Mark,

I appreciate your analysis of the many variables. It would have taken me days and days looking at the data to come to the conclusion that you expressed.

From what you write it sounds to me that if one is really interested in permanence with inkjet printing a 100% carbon pigment ink set is required, as well as proper paper selection.

My own interest in this is more academic than practical because while I do make inkjet prints my primary printing is with carbon transfer, where fading is less of an issue with pigments other than pure carbon because of the agglomerate size.

Sandy King

[MHMG]

Mark,
..From what you write it sounds to me that if one is really interested in permanence with inkjet printing a 100% carbon pigment ink set is required, as well as proper paper selection.


My personal view is that any system that achieves AaI&A Conservation Display Ratings exceeding 100 Megalux hours for both lower and upper limits has robust enough light fastness that other factors (heat, humidity, air pollutants) are more likely to lead to visual changes in the print than light over time if the print is being displayed under "typical" home display conditions. Daily light levels for 90% of prints on display in most homes are less than 200 lux. Of course, that other 10% is where the light fade issue can takes it's toll more quickly, and many print buyers take no precautions about light even though they are relatively simple to implement. Thus, even more light fade resistance is always a good thing when a print has it. By my 100 Mlux hr rating recommendation, only the Cone Carbon set meets the criterion, but there are numerous Epson, HP, and Canon OEM ink grayscale modes that when married with the right paper will meet the 100 Megalux hour benchmark.



My own interest in this is more academic than practical because while I do make inkjet prints my primary printing is with carbon transfer, where fading is less of an issue with pigments other than pure carbon because of the agglomerate size.
Sandy King

Yes, particle size, aggregation/agglomeration, and surface-volume aspects of how the pigments are applied can create a sacrificial layer for both pigments and dyes such that fading won't be observed as easily. An excellent example of "sacrificial" ink loads can be seen in AaI&A sample ID# 181. It's a single channel Epson Claria dye-Black only monochrome print. Dmax with the ink's excess ink loading has only changed 0.8 delta E in test at 70 Mlux hours of exposure, while the same black ink, jetted in lower drop count to make light and mid tone grays, shows delta E values greater than 12 for some of the light and midtone gray patches. I tried to explain this surface-to-volume ratio issue to an ASTM committee working on an international standard for lightfastness of digitally printed art. I told the committee that the tested materials absolutely have to be produced as a system, ie., printer, ink, media, and even software driver choice (it controls ink drop placement and blending), but they rejected my work and my test methods because they want their new digital test protocol to conform to the way they test paints and pencils, ie., hand applied with delta E changes sorting the inks into different light fastness categories. Good luck with that was all I could say at the end of our lengthy discussions! The committee wasted a lot of my time.