How does the choice of a glossy paper influence the fading of dye inks

[Ink stained Fingers]

I'm running a fading test since 2 weeks to compare various photo glossy papers how dye inks fade on these.
I'm using the same dye ink set, the same printer and driver settings and use a range of different photo glossy papers - Sihl, Tecco, HP, Canon and some more - most of them of the RC type with a PE barrier, the more expensive ones vs. the cc castcoated papers. This test does not cover any non-standard papers , special inks or other experimental actions like a GO overprint.
The samples are placed outside with some winter sun and freezing temperatures - ozone and UV will do their work.
I did a similar test about 2+ years ago showing quite some differences between the papers tested at that time, I 'm using now a few more papers - and at some different environmental conditions vs. the summer sun at that time. The first differences are becoming visible now, I'll give the patches some more time to show the variances more clearly for a more detailed report.

 

[Ink stained Fingers]

Please let me give an update on some fading data now after 3 weeks - standard papers, standard inks, nothing special, no GO, no swellable papers and such with

paper #1 HighGloss 260 by farbenwerk.com - private label
paper #2 Glossy 240 - a budget RC paper by a Polish Ebay supplier
paper #3 Labelheaven 230 - the only castcoated budget paper in this run
paper #4 HP Premium Plus Glossy Photo Paper
paper #5 Canon Pro Glossy Paper
paper #6 PG230 by Tecco
paper #7 HP Advanced Glossy Photo Paper
paper #8 Netbit Glossy by Aldi
paper #9 Sihl Glossy by Aldi

All papers - except # 3 - are RC papers with a PE film barrier, prices range from 10ct to 60ct per A4 sheet
Measured are the lightness changes of the CMYK color patches in comparison with prints kept in the dark.
Numbers range from 0 - 255 in the 8 bit binary range.



Paper#___1____2____3____4____5____6____7____8____9

_____C__19___17___11___21___20___17___16___20___19
_____M___4____5___13____5____3____5____7____4____6
_____Y___0____0____1____1____0____0____0____1____0
_____K__12___14___38___15___10___12___14___14___15

_Total__35___36___63___42___33___34___34___39___40


#3 - Labelheaven - fades the most, the other papers are rather close together when looking
to the totals, but there are some differences when looking individually to the performance of cyan or black inks.
I didn't measure the gamuts of these papers for this test specifically, but there are no significant differences as measured with another ink, the Fujifilm DL ink. So far more expensive papers don't stand out at all with significantly better fading performance than
the Aldi 10ct sheets #9 and #8. All these RC papers perform quite similar. There may be other reasons to select one paper over the other (and pay for it) - e.g. paper weight, special discount offers, the look of the gloss, the ink limit, compatibility with pigment inks

 

[Ink stained Fingers]

Please let me add some info how the optical brighteners in these papers are doing.
This is the collection of patches sorted together - the left ascending row are the prints kept in the dark and the right row of patches are the exposed patches during the last 3 weeks. The numbers refer to the description above.




The HP papers #4 and #7 and the Glossy 240 #2 from Poland don't contain any OBA's, the OBA's in the Sihl paper #9 are apparently fading the fastest, and the other papers show as well various levels of fading of the OBA's.

 

[peter D]

The OBA performance test you have done is somewhat at odds with what I'm observing using my 365nm LED torch to examine what is happening to the 3 or 4 paper fade test looking at two swellable papers verses microporous Canon Semi Gloss.
So far well over 3 months after the start of the test the swellable HP Premium Plus Glossy which has a low OBA content has changed the least and Canon Semi Gloss with average OBA content has changed but not that much. The Giant Image swellable (both gloss and satin) with a high OBA content is also not changing that much either in the amount of blue light emitted under the UV torch.
Certainly to the eye under normal window filtered daylight light the whiteness of the prints has changed a bit but is only noticeable if I do a side by side comparison with unexposed papers. I also examined them under direct bright sunlight which increases the difference but only slightly. There is still a distinct whiteness difference between paper with high OBA content and the low OBA content paper (HP Premium Plus Swellable).

Could it be that my indoors test that is trying to replicate typical residential display conditions (although my window glass has a very light grey tint) is less detrimental to OBA performance over time than the outdoor test that you are doing? If this isn't the case then is there a difference between the types of UV illumination we are using ie. a wavelength difference? Many of the LED uv torches on the market radiate at near 400nm which might produce a different result to what I'm seeing.
At the end of my fade test I'll try to include a photo of UV light test on the papers I've used. My torch puts out a fairly narrow beam so I might not be able to show a range of papers in one shot.

 

[Ink stained Fingers]

I took the photo with a blacklight neon tube which emits still a small amount of blue-violet visible light, the UV of the spectrum is activating the OBA's. I don't see how the viewing light would impact the fading performance. Different test conditions may lead to different fading effects, I'm mainly going after the question whether I would need a paper with OBA's and what their benefit is. I have not seen any - the OBA's fade as quick as the inks, and the papers w/O OBA give me the same white level as papers with OBA's, the Sihl glossy with OBA has a more yellowish tint than the HP papers without - the HP paper gives a more neutral white look. And gamuts don't make a relevant difference either. Since most of the prints are viewed indoors with a pretty small UV level OBA's won't get activated anyway to create some effect. You do not run your home illumination office like with daylight neon tubes which might make brighten up copy paper. The issue may be more critical for B/W prints in the lighter gray to white range creating a different tint under different lamps.

 

[Ink stained Fingers]

I'm closing this test now after 5 weeks - how the same inks fade on different papers, I have added a 2nd column to each paper, in the same paper sequence as above

Paper#____1_______2_______3________4_______5_______6_______7_______8_______9

_____C__19-23___17-24___11--16___21-28___20-27___17-23___16-23___20-26___19-28
_____M___4--8____5--8___13--25____5--7____3--5____5--8____7--9____4--7____6--8
_____Y___0--0____0--0____1---6____1--0____0--0____0--0____0--1____1--0____0--0
_____K__12-20___14-22___38--71___15-21___10-19___12-20___14-21___14-22___15-25

_Total__35-51___36-54___63-118___42-56___33-51___34-51___34-54___39-55___40-61

The totals of the luminance changes range from 51 to 61 except with paper #3 -
a cast coated budget paper with 118 doubling that.

Paper #3 looks pretty bad already , the other papers stay in range.
There is no reason to select one paper type over the other for the
reason of a better fading performance, all papers (except #3) are
PE/RC type papers.
The OBA's are almost gone in most papers except in the Canon Pro and Tecco PG230 #5 and #6 ,
companies seem to use different OBA chemicals to this effect.