Fading of Inkjet Papers

[Ink stained Fingers]

But there is another property of possible interest - just slightly adding to the complexity of this subject, it is easy to extract the black levels of the paper/ink combinations from the scanned data. I'm using just one black ink in this test - the Epson 106 ink - in combination with the GI53 CMY inks. So all data are relevant to the paper performance (I didn't want to spend the money for the Canon black ink...)
Most black levels of the listed papers vary between a L*=3.5 to 6.5 - nothing spectacular or surprising, but with some exceptions, copy paper shows an L*=27.4 which is typical, and the Epson inkjet paper is about the same. That's all no surprise. The HP Premium Plus Photo paper just gets a L*=7.86, this paper gives the ink a good fading performance but has a pretty weak black level. And the other surprise paper is the Hayatec cast coated paper with the poor fading performance mentioned above, this paper has the darkest black level in this test of L*=3.88, so the more you dig the more irregularities you find of this type.
And I have some more of such 'funny' results to come.

 

[Ink stained Fingers]

Let me point out a hidden weakness by using the patch sheet above; there is one black patch - printed with black ink, but the driver is transitioning very soon darker grays and colors into a mix of CMY inks, the black ink is just used for about the lowest 5% of a gray ramp, and transitioning in the range from 5% to 10% to the CMY colors and not using the black ink anymore. I'm not adressing special printing modes - B/W - grayscale printing - advanced B/W and similar and not the use of light gray inks either, they are not directly accessible to the user. This all just means there are only a very few patches actually printed with the black ink - probably 3-5 . The black ink may fade faster or slower than the other inks, and calculating an average over 96 deltaE values just means that the black ink performance is underweighted in the average, the CMY colors - mixed and pure - are represented by about 90 patches - assume 30% per color but the black ink just contributes with a few patches to the average.
I don't know whether that causes a change in the ranking sequence, but I'll add a few more dark patches to my patch sheet for consistency reasons once these tests are over.

 

[Ink stained Fingers]

Let me describe the most simple fading test setup possible after all those details, you don't need any sophisticated equipment or software, no calibrated scanner either.
You just use 2 color patches - one printed with black and another printed with a middle gray, gray colors are printed as a mix of the CMY inks, so don't use any special B/W or grayscale printing options in the driver in this case, print these color patches in any size and shape onto the paper you want to test or with inks you want to test, print 2 sheets with the same ink/paper combination - one print gets exposed - the other one kept in the dark for reference to compare with. I'm placing my test patches outside, this accelerates the test significantly, any other place is suitable as well but the test cycle may take longer e.g. indoors.

Scan your patches after exposure of a week or longer and use the histogram function most photo editors provide, some give you a numerical readout of data as the one I'm using in Paintshop Pro or the Epson Twain scanner driver. Some software let you display the luminance histogram but with no numerical readouts, just make a screen print in that case and use a ruler to measure the distance of the peaks in the histrogram.

You see the reference patch and the target under test, the histogram shows 2 peaks for the black ink patches left at the dark end of the diagram and 2 peaks in the middle for the gray patches, just measure the distance of those peaks for the black and the gray/CMY combined inks and do a few more measurements after some time - within a week or 2-week interval.

You easily can compare a few different papers this way - the patches printed with the same inkset - or you compare different inks - with the patches printed onto the same paper. This type of test should allow an easy test if you want to change to a different ink - for whatever reason - cost in most cases, but be aware that 3rd party inks don't perform as good as OEM inks. But if you are already using some 3rd party ink and want to switch to another ink this test could easily tell you whether that makes sense. There are rather bad and very very bad inks on the market in this respect but no supplier would tell you and don't believe any claims like 'UV resistant' or similar.

 

[Ink stained Fingers]

The 96-color patch sheet contains a few patches for which I track the data individually - a middle gray patch at M1, and Cyan and Magenta at K7 and J1. The gray patch let me see directly how the color shift of the gray patch relates to the overall deltaE average and how the results with the simple method above is matching or diverging vs. the average calculations. The simple mode does not deliver exactly the same results as the 96 patch average method and would change some of the ranking in the middle field with results which are rather close, but the best and worst papers remain as mentioned in posting #8, the cast coated papers are the worst performing papers and the HP paper at the top regardless of the measuring method - with an exception - the Canon PT101 protects the black ink better than any other paper but not the other CMY inks. The fading of a particular ink color is independent from each other - which as well becomes visible with the C and M inks.
Cyan and Magenta are fading with different speed - different deltaE's - but there is a rather strange effect that the ratio of deltaE-Magenta/deltaE-Cyan varies tremendously between papers as if there are chemical reactions with one or the other ink and the coating, just to give some examples


_______________deltaE-Mag--deltaE-Cyan____ratio

HP Prem Plus_____8.55_________5.59_________1.53
Canon PT101_____6.51_________6.71_________0.97
Hoyatec__________4.38________12.80_________0.34
Hahnemühle
Baryta Gloss_____14.17_________6.42_________2.20

There is a wide spread between the deltaE's of Magenta and Cyan, under the same test conditions and the same sun.

 

[maximilian59]

The HP Premium Plus Photo paper just gets a L*=7.86, this paper gives the ink a good fading performance but has a pretty weak black level.

I have some older measurements with the HP Premium Plus Glossy 300:
These are L*, a* and b* figures.
With a Pro-1000 you get very low L* with a nearly neutral black. Even with the Envy Photo which uses only the three colors on glossy paper it is ok. Only not very neutral. Patches printed with printer manages color. On the Pro-1000 I took PT-101.
This shows clearly papers have very different black values depending on the ink and printer. In the coming week I will print samples with CLI-42 (Chromalife100+) and Epson 106 with a XP-7100. Let's see what comes out.

 

[Ink stained Fingers]

This shows clearly papers have very different black values depending on the ink and printer.

Yes, very much, and you could draw up a multidimensional performance matrix with all those elements, parameters and test methods, and pigment inks are a different game again. That was the base for my attempt to come up with a test as simple as possbible which still delivers some reasonable results - whether it's with 4 CMYK ink colors or just 2 - black and gray. Using a spectro and i1 software delivers many more details and can help explain curious findings but such tools are not available to the majority of refill ink users. It actually started many years ago when I didn't know which ink to buy - e.g. from Octopus office - Inktec - OCP or Octopus Fluids - information was not and is not available to the detail level like gamut volume, black level, fading performance so I started to do my own tests and it got more - with Chinese inks - Fotonic XG and many more until I found the Fujifilm inks for the Drylab printers as an OEM ink comparable with the 106 inks and quite affordable in expired larger cartridges.

So let's continue the game................

 

[Ink stained Fingers]

I'm using a patch sheet with 96 fields for the recent fading tests, this let me create an icc-profile as well showing how the gamut is shrinking, this is a view of the gamut volumes after 1 - 3 - 5 - red - blue - gray - weeks of exposure at the mid luminance of L+=50

The volume is continously shrinking, and the image shows as well that the gamut loss varies with the color - ink colors are fading with different speed.

The loss is more dramatic at the darker range, here at L*=28

The black is almost gone after 5 weeks already, this LS250 paper let the black ink fade much faster than other papers.

 

[Ink stained Fingers]

I scanned the papers under test - listed in posting #6 - now again after 4 weeks of exposure, all samples printed with the same inkset CMY with Canon GI 53/Chromalife 100 inks and an Epson 106 dye black, they are barely mixed at all on the 96 patch fields .

My findings stated already above just consolidate, there are no other changes or surprises to my comments in posting #8,

- the HP Premium Plus photo paper fares as the best as judged by the average deltaE of all patches with a value of 8,67

There is a group of papers following pretty close

- the Canon PT101 - 11.73
- the Emblem photo glossy 240g - 11.82
- the Glossy 240g/Ebay - 11.74
- Mediajet Baryta - 11.06
- Hahnemühle Baryta - 10.97

- the papers with the poorest performance are the Hayatec cast coated glossy and the LogicSeek cc glossy, the other papers not listed rank in between.

And there are a few details to mention which are quite unusual compared to the performance of the other papers with this inkset

- the PT101 with the 106 black ink delivers by far the best stability - with a deltaE of just 0.95, the worst is the LogicSeek with a deltaE of 23.5 , this could be interesting for somebody doing B/W prints in B/W mode which just uses the black ink and dithers the gray tones.
It is interesting to see that the paper coating seems to influence the performance of individual colors, the black ink in this case is protected much stronger than on any other paper - typically with a deltaE between 3 - 4.
A similar effect can be observed with the Hayatec cc paper protecting the magenta ink much stronger than the cyan ink - magenta/cyan = 0.65 whereas this deltaE ratio is typically between 1.2 and 2.0 on most other papers , there mut be some very specific reaction happening between a particular color/dye of an inkset and the paper coating.

 

[stratman]

the PT101 with the 106 black ink delivers by far the best stability

Wouldn't it be funny if the 106 ink performed better than Canon's Chromalife + inks.

Embarrassing.

 

[The Hat]

Wouldn't it be funny if the 106 ink performed better than Canon's Chromalife + inks

For Who, them or us...