Fading of Inkjet Papers

[Ink stained Fingers]

I'm currently testing a mode to simplify my test mode for the fading of inks and papers,
one approach is the use of the i1profiler software with additional convenience and options ( I paid for ) and as well a simpler way to use a scanner and the histogram function to which I'll come a little bit later, the rail with the color patches is full at this time.

I'm using a small target patch sheet to create profiles, this patch sheet can be smaller than 10 x 15 cm, it's actually 11 x 6.5 cm, with 96 colors, and is printed with the Epson 106 inks



I scan this directly (+ a few hours ) after print and one week later again - on two papers at this time - a budget level cast coated Logic Seek 250 gr and a HP Premium Plus Photo Paper
The gamut of these papers differ - not by so much but it's as well the haptic of the paper and it bends slightly once printed - the Logic Seek paper is much cheaper , you can use it with these limitations in mind, the green line is the gamut curve of the LS250 paper at L=50, the HP paper has the wider gamut, and this as well at other L-levels.

Such gamut differences are quite typical between glossy inkjet papers, I'm now comparing the gamut of each paper after one week exposed to the sun and ozone etc,
this is the plot for the HP paper

The dark line shows the gamut after one week - there is a loss mainly in the upper quadrants , not all CMY inks fade with the same speed

The gamut loss on the LS250 paper is shown here -with the blue line after one week

It is too early yet to see if one paper let the 106 inks fade faster than the other paper - probably yes - I'll give the patches some more time under the sun and post any findings in a few weeks.

 

[The Hat]

I'm currently testing a mode to simplify my test mode for the fading of inks and papers,

It’s very cruel to see what the normal environment can do to our lovely photo prints when we use 3rd party inks, but its an necessary evil just to let us know there are no free dinners.. I really do appreciate all your great work Ink stained Fingers and the time it must take.. Patients, patients, patients..

P.S. Hint, hint… While waiting on your oven tests to cook and complete, why not get into 3D printing…

 

[Ink stained Fingers]

why not get into 3D printing…

I did already some 3D prints

 

[The Hat]

I did already some 3D prints

Brilliant, I hope @stratman is watching..

 

[Ink stained Fingers]

And now let me describe the simple mode - plese create a very simple patch sheet - with 2 patches and print black onto one field and a medium gray onto the other field - 1x1" or 2 x 2 cm - id does not matter. Print one patch sheet with the ink or paper under test and a 2nd one as a reference - with your standard ink and standard paper - I'm using the Epson 106 inks as you probably have recognized already, and I use a HP Premium Plus Photo Paper and/or a LogicSeek cast coated budget paper.
Why a gray patch - gray is printed with the CMY colors - all together in a particular fixed mix if you use that gray value again for another test. So this peak shows a kind of average of these 3 colors.

I'm getting this display with my 3490 Epson scanner with a pre-scan - just two peaks for the black and gray patches, the 3rd patch is for the paper white.

I can move the left black triangle - the adjustable black level for the main scan - underneath both of the peaks and read the luminance levels - 19 in this case for the black patch, and I move it over to the peak of the gray and read the level there as well - that's it.

I place the patches into the sun and do the same readings after a week or 2 or 3 , record the resp. levels and calculate the differences to those numbers recorded directly after the print. And these deltas most likely differ and tell you which ink or paper fades fster/slower - in relation to each other.

If your scanner does not give you these data, you can use the histogram function of PaintShop Pro which looks like this

You do a readout of the luminance along the x-axis after print and after a week or 2 again - the red spikes shifted to the right, and you do the same calculations as above .

 

[Ink stained Fingers]

The inks of the new printers - Canon Pro-200 - G650 - GI-53 and Epson ET 8550 - 114 have been tested and results been reported in several threads. @maximilian59 tested as well a range of different papers here

https://www.printerknowledge.com/th...ing-test-update-26-may-2021.14742/post-128221

showing a wide performance range how much a particular paper can protect or almost kill an inkjet print with dye inks.

I started a test a few days ago - just with one ink - the Chromalife 100/GI53 ink of the G650 Canon printer, and I'm using a WF2010W for all tests with the same driver settings.
This is my collection of papers under test - a pretty arbitrary collection of papers which I use - more or less frequently at this Corona time

- Epson Inkjet paper

- PhotoArt White Baryta 310gr by Mediajet

- LogicSeek 250gr - a budget level cast coated glossy paper

- Hahnemühle Photo Gloss Baryta 320gr

- Sihl Baryta Satin 295gr

- Farbenwerk FineArt Bright Velvet 275gr

- plain Copy Paper

- Hayatec 240gr - a Chinese cast coated budget paper via Ebay

- Canon PT 101 Pro Platinum

- HP Premium Plus Photo Paper

- Glossy 240 - a budget PE paper via Ebay

- Emblem Photo Gallery Glossy 240gr

The sequence on this list is arbitrary and does not indicate any ranking at this time, I'm doing this test with the 96 patch test chart shown above and i1Profiler software.

 

[Ink stained Fingers]

Not everybody has a i1Profiler setup to run such tests; I ran my tests until now just with theCMYK 4 color patches and readouts via the histogram function of PaintShop Pro, and I'm running a test now to simplify such a test for orientation even further by using just 2 color patches - black and middle gray. Gray is printed typically as a mix of the CMY inks, so all ink colors are covered. This test is supposed to deliver some relative ranking between the items under test - either inks or different papers - and I want to find out how much this test approach delivers the same or different results to the test with the i1Spectro and software. This test does not require any sophisticated equipment or software, not even a calibrated/profiled scanner but just a way to make histogram readouts since all testing is relative for the items under test - e.g. relative to the performance of the Epson 106 ink or a particular paper you choose as a reference . I'm showing above that the necessary readouts can even be done with the scanner driver software which I'm using.

I'll report the first findings in a few weeks - I don't have a feeling at this time how this will work out at all.

 

[Ink stained Fingers]

The papers listed in my posting #6 above have now been exposed to the sun, ozone etc for 2 weeks, so let me give you a status how these papers perform - as measured with my 96 color patch sheet and the overall average of all deltaE changes of these patches calculated by the i1Profiler software, the patch sheets had been printed with the GI53/Chromalife inks - CMY. I won't list all papers with individual numbers or a one by one ranking, there are some parameters or changing the overall method which can deliver quite different results.

The HP Premium Plus Photo Paper stands out in this test so far and rates at least 30% better than any of the other papers, it is a premium paper, does not carry much optical brighteners and is pretty expensive overall. I succeeded to get quite some supply via Amazon as 'used' - customer returned boxes sold with a steep discount - ' a few pages missing ' or 'outer package damaged' or with similar comments.

There is a small group of papers at the low performance end - that's the LogicSeek casted coated paper and the Hayatec cc-paper . They fade almost 3x faster than the HP paper. It is valid for these papers to say that you get what you pay for - these are budget level papers in the lower pricing range. There is nothing wrong with these - you just need to balance price and performance.

And there is a middle range with all the other not yet mentioned papers, their performance is quite close together by the deltaE numbers - there is not much of a difference between an inkjet paper or a Baryta paper or the Canon PT101 at this time.

This is a test with one ink only, the GI53/Chromalife ink, switching the ink can introduce wider changes of the ink/paper performance as already shown elsewhere several times, so I won't repeat such test with these papers but another ink set. I just can repeat my recommendation to stay away from 3rd party dye inks if not absolutely necessary - Canon and Epson offer a good range of bottled and affordable dye inks at this time.

 

[Ink stained Fingers]

Let me show you some details of the measuring methods to run these fading tests. I was using a simple approach intentionally in the past - no need for expensive software/hardware like the i1Profiler package, I was tracking the luminance changes of 4 color patches with the C M Y K colors printed onto the paper target under test -and with n the ink under test or for reference, and I was tracking the luminance changes via histogram readouts of the scanned patch sheets , this test is consistent in itself, I'm recording the changes of the CMYK prime ink colors , can repeat such a test and I can compare results with different inks and papers, and about everybody could do that the same or a similar way.

Using the i1profiler package - with the i1Pro2 spectro and the resp sofware - you can do more - scan more patches, get more calculations done, but this adds variability into the measuring process.

I'm using a 96 field patch sheet which I otherwise use for profiling 4"x6" papers, the target image just fits onto 1 sheet. And I'm using it as well to track the color changes of the patches. The layout is quite simple - an even distribution of control points aover the complete RGB color space - all corners and edges occupied with additional control points and more inside the RGB volume. You can get a 3D view like this:

The pure CMYKRGB colors are located at the corners of the RGB cube.

But this choice of a layout is arbitrary, @maximilian59 is using another layout - with 2x30 patches, with 5 step color ramps of the CMYRGBK colors, and a few more mixed colors

The image looks somewhat different - the control points are not that well defined and distributed differently - tending more to the lighter side.
This patch sheet actually does not have 60 colors but 1633 colors when you do a 'count unique colors' command, the color patches are slightly dispersed, problably from a prior jpg compression or a resize action which creates additional colors by interpolation along edges, neighbouring pixels etc. But this does not really matter very much for the fading test.
It's at the end the average of all color changes which are recorded, and it may not make much of a difference, I just start with an overall darker patch image level - there is more ink on the paper when the test begins. More relevant could be the color distribution and their weight in the average at the end.

Let me have a look to the overall lightness of images - of this test image

The luminance histogram of this image looks like this

50% of the image pixels have a luminance of 117 or less, and the other 50% of the image pixels are above, that's very close to a middle gray.

I do the same with the patch sheet to look for the lightness distribution

50% of the pixels are at or below a lightness of 135, and the other 50% above, so this patch sheet is slightly lighter than the test image, but please keep in mind that there are white separator lines which raise the lightness slightly. (The unique color count is 90) .And now to compare with the other patch sheet

The median (50%) is at a luminance of 168 - significantly lighter than the test image.
(The numbers along the x-axis - luminance - are discreet - there are no 167.5 or other fractional numbers possible to hit the 50% exactly. The x-axis goes in 1 bit steps from 0 to 255).

I don't know whether and how much all this makes a difference for the actual readings and the results and for the ranking of the papers or inks, there are some other funny effects I'll adress separately.

 

[Ink stained Fingers]

There is more I can add to the complexity of longevity testing - I actually don't like the expression 'longevity' in this context so much - measureable changes show up already after a few weeks of exposure and that's not 'long' for me in Canon terms of 100 years, 'generations to come' etc.
Let me put a small focus on optical brighteners, those which interact with the UV part of the sun light.
I could do a readout of the patch sheets reading their white level with the M0/M1 or M2 measuring methods - with or w/o OBA effect, reading the white levels both ways and tracking their changes - OBA's fade as well, but I don't in this test cycle.... limiting the complexity of the test....I just did a quick check with a UV flashlight - the Canon Platinum Pro shows the highest level of OBA's, higher than in other papers , it is standing out in this respect, and there are a few papers with a low OBA level at the other end - the Sihl Baryta Satin 295, the Mediajet Photo Art Baryta White and an old Epson Inkjet paper, and all the other papers listed above are somewhere in between, but OBA's are not the main subject of this thread.