Fading of patch sheets in the dark

[mikling]

Here's the thing. In the real world pigment inks even aftermarket ones far outperform dye inks even OEM. That indicates that for many situations the test performed by the above outfit leaves a lot of real world issues out. I can point out a flaw in the process that parallels a flaw NASA made and subsequently discovered in the 60s in simulating aging but I won't open up a can of worms. ( Here's a hint, fading occurs at the electron level and involves energy levels. Can we get a "soft" action in that process. What happens when you increase the energy levels... is the effect proportional?)
In nearly 20 years of using aftermarket pigment inks, I know of really no one who has been disappointed and never had to address any issues in that area. That to me is the real world. I always recommend using pigment inks when fade is a concern and with printers that can output prints that can come close to the best dye ink printers,
Go with a pigment ink printer that uses CO or GLOP and most will be pleased.
Back in the 70s according to all tests performed to that date indicated all amplifiers should sound the same when they showed the same results in the tests. They did not. The tests performed were inadequate. Pity those thinking the tests were correct because the tests omitted many issues not yet uncovered. That is science. Once you discover facts that do not track the tests, you need to question the test and its validity and start over again with newer and more sophisticated testing. Otherwise you MUST warn the viewer of the limitations of the tests performed.

 

[Ink stained Fingers]

You are right that we shouldn't open a can of worms in this forum nor tracing NASA flaws, but it would help a lot for users here to understand whether the Wilhelm Research documents referred to have still some validitiy or none at all - and if that flaw affects as well other test reports of that institute.
But beyond that I think we can close the discussion at this point. I just will report the dark fading data of my current test as the data develop over time

 

[aCuria]

A test with 107 inks would be greatly appreciated

 

[Ink stained Fingers]

A test with 107 inks would be greatly appreciated

Please see here

https://www.printerknowledge.com/th...6-107-114-t54c-bottled-inks.16040/post-139351

 

[aCuria]

Please see here

https://www.printerknowledge.com/th...6-107-114-t54c-bottled-inks.16040/post-139351

How long do you think I should dry the prints before making a profile with 107 inks?

 

[Ink stained Fingers]

How long do you think I should dry the prints before making a profile with 107 inks?

You see in the reported numbers that the colors are drifting for quite a while, I'm normally scanning the profile patch sheets after a day to calculate the profile, I may do it quicker - e.g. after one hour - to get a feeling about the profile - like profile volume or black level, but I rescan the sheet after a week for paper profiles which I'm going to use for a longer time.

 

[Ink stained Fingers]

I did another measurement cycle after 3 months - the patch sheets were kept in the dark for this period, the previous measurements were done 1 month after print and posted in #5. I'm showing the total averaged color shifts for the period from 1 hour after print till today after 3 months and as well the incremental color shifts for the period from 1month after print till 3 months. It is interesting to see that the Inktec inkset performs quite similar as the 106 Epson inkset. There are variations as well with different paper tpes - OEM HP and Epson and 3rd party LS270 and Hayatec. There is at this time after 3months no real benefit of OEM inks and papers vs. 3rd party material. I may do another measurement after a year or so if I don't misplace the patch sheets in the meantime.

 

[Ink stained Fingers]

I found some instructions by Brother how to dry and store photos after printing, Brother specifically mentions that the colors of inkjet prints need some time to stabilitze, this is very important for the profiling process when patch sheets are printed and scanned, and for judging the color fidelity of inkjet prints directly after print.

 

[Ink stained Fingers]

I did another scan of the patch sheets now after 9 months - I'm measuring the fading of dye ink prints which are kept in the dark, just with a short exposure to the light for the measurements. I'm comparing prints of an OEM Epson 106 inkset with an InkTec inkset, with the patch sheets printed on 4 different papers - 2 OEM - Epson Premium photo paper and the HP Premium Plus Photo Paper and with 2 cast coated papers LogicSeek 270 g and an Hayatec 240 g. The table shows the averaged deltaE's for 96 patches and for a time period of 1h after print up to 9 months and a time period of 1 month after print up to 9 months in the dark .

The numbers show that the fading in the dark does not stop after 9 months, in any combination of OEM inks and papers vs. 3rd party inks and papers. But be aware that the numbers are pretty small already and coming close to the measuring tolerances of the i1Pro2 spectrometer.

The inkTec inks perform quite well but the OEM 106 inks run better overall on most papers, and the OEM papers seem to let the OEM inks perform better than the Inktec inks, but the test base is too small to draw final conclusions, the results vary depedning on the ink/paper combination which is about the same situation as with the fading tests exposing the patch sheets to the sun and ozone.

 

[Ink stained Fingers]

The table above lists averages - the average drift of 96 color spots per measurement in time, there is much information hidden in the details of every measurement, let me just take one example - the inktec ink on the Hayatec cc-paper after 9 months - in the bottom right corner showing a total av. color drift of 5.54 . But how do individual inks perform:

total____5.54 DeltaE
Black___0.80
C_______6.02
M______2.71
Y_______3.36
Red____1.30
Green_10.57
Blue____7.62

There is quite a difference between the Cyan and Magenta inks - what will happen - color spots in an image mixed with cyan will fade faster than mixed with magenta - color prints will drift to a reddish tone over time when loosing cyan. The performance of the black ink is much better than any of the other inks - all information which gets lost when just looking to the averages. But there is about nothing a user can do - swapping this or that ink from another manufacturer or using another paper - but the information to make such decisions is just not there, I haven't seen such tests at all by Wilhelm Research or Aadenburg or the printer/ink manufacturers like Canon , Epson etc.