Fading of patch sheets in the dark

There is another varible you can look to - which color is drifting the most in these 9 months. it is in this case a saturated green which is drifting by a deltaE of 12.59, and such a drift by a saturated color is averaged away by the lighter colors which drift less - there are just less dye molecules which can change over time.
 
ptprintfan said:
Just out of curiosity, have you ever tested the the change of the paper itself?
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You would need to differentiate between papers with and w/o coating, the coating should cover up most of the paper related effects. And there is one more culprit - the optical brighteners act like other dye inks - they fade as well - even pretty fast , even faster than some inks . I have shown the effect in various previous postings, as well a spectral display of the paper white before and after exposure. The OBA's in coated papers are embedded in the coating, not in the base paper itself. And there is even a more serious effect - those OBA's don't just disappear but they cause yellow staining over a longer time, Aardenburg has published a document about this effect rarely taken into account.
Some comments here:
https://www.aardenburg-imaging.com/...n-archival-pigment-and-other-fine-art-prints/
https://www.aardenburg-imaging.com/optical-brighteners-obas/

So there are various effects overall overlapping each other and making it a pretty complex job to assess the overall fading performance of a given ink/paper combination. Since these effects are independent of each other simple reciprocal extrapolation of test results is just not possible, I just post the test results and the way how I got them to get some 'feeling' how different inks/papers perform under the tests as posted, I won't convert them in 'mega display hours' or alike, I don't have a lab in which I could do tests with exactly the same environmental conditions. The dark fading test is rather simple in this sense - there is no way to accelerate it - a darker than dark test environment is not possible.
 
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Let me update the fading results after 1 year with the patch sheets kept in the dark, but w/o any specific additional archiving precautions e.g. albums with acid free paper, special boxes or whatever. It appears to me that some ink/paper combinations are drifting slower since the last report - 9 months after print. I'm listing here the average of the color shifts of 96 patch fields after 1 hour after print to 1 year and 1 month after print to 1 year. The differences between the Epson OEM 106 ink and the InkTec ink on OEM and 3rd party papers are not very big overall but every ink/paper combination delivers a different result - it is not possible to generalize the findings overall that this or that paper or ink is always better.

I'll keep this test going, but since it is not possible to accelerate a fading test in the dark it'll take a while for more results - probably in a year.


Dark Fading 1y.png
 
Le me update the upper table after another year - the complete fading of patchsheets after 2 years.


Dark Fading 2 years.png


It is interesting to see that the paper type very much defines whether colors shift less with the OEM 106 ink or the 3rd party InkTec inks. The amount of fading in an album or similar is defined by the paper type, and much less by the assumed long term stability of an OEM ink - in this test the Epson 106 inks. The overall fading of a long term period from 1 year to 2 years shows that inks are still drifting at a pretty low level but not zero.
 
I followed all your tests and although you several times mentioned that the paper is a really important factor for fading and ink behaviour, I actually realized it just now when I had the struggle with the pigment inks on the Katana papers and saw actually how really important is the media and not just the inks. Thank you for all your tests and keep up the good work.
 
It appears that for 106 and Inktec on Epson and HP paper, the average fading is almost complete after a week to a month--a month if you want to be quite persnickety. Even an hour isn't bad. I think the remaining drift over a year or two is not likely to be very visible--although I"m not sure about cyan and saturated green.

But in any case, I don't think the long-term drift should be part of profiling. It's rather difficult to determine the future appearance in a year or two, and it might not be very helpful to try to predict this with profiling.

There is one trick that you might try, however. Ansel Adams was confronted with the same problem. When he did proofs to optimize the appearance of a print, he put the prints in the microwave, to get them good and dry and display their final appearance. I wouldn't try to nuke them--just microwave them long enough to get them good and dry, and simulate that 1 week or 1 month appearance for profiling. As a big time saver it might be worth a try.
 
Microwaves - thanks for the tip - I might give it a try with the next long term fading test - whenever; I just will keep this test going .
 
Yeah, just dry a new print and compare it -- visually or otherwise -- with your aged prints.
 
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