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Author Topic: What happened to Wilhelm , did he die or something.  (Read 8776 times)

Alan Goldhammer

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Re: What happened to Wilhelm , did he die or something.
« Reply #20 on: May 22, 2017, 03:06:14 pm »

I spent five years on an ANSI technical group some years ago.  Getting to consensus on issues can sometimes be difficult and I'm sure that this is what happens in the photography area.  ANSI (American National Standards Institute) is the US member to ISO which is the umbrella group of world standards organizations.  Technical work groups are pretty much open to participation to those with expertise and time to work on projects.  There is no compensation from the standards organization for such work.  There's a whole process that has to be followed for the development of a standard.  If the major vendors of ink jet printers and inks want to slow things down, it's not difficult to do (I have no knowledge of whether this has or has not occurred). 

Here is the current list of TC42 (photography) projects:  https://www.iso.org/committee/48420/x/catalogue/p/0/u/1/w/0/d/0  You can see all the published standards by ticking the appropriate box.  The ISO group did a lot of work on film speed and processing chemicals in the "old" days.

I've read a number of the Wilhelm papers over the years and have also supported the Aardenburg work both by contributing funds and doing an extensive printing test of Hahnemuhle Photorag Ultrasmooth where Mark suggested that we look at all aspects of the Epson ABW print driver as well as the colored inkset.  I like the work Aardenburg has done as it's transparent as to the methodology and makes good sense.  The results are there for everyone to examine.
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Mark D Segal

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Re: What happened to Wilhelm , did he die or something.
« Reply #21 on: May 22, 2017, 04:46:44 pm »

Hahnemuhle is always saying their presence doesn't matter, but that is a relative judgement. It is true that hah photorag 308 did fairly well in my submitted Aardenburg tests many years ago, but not as well as the papers with no oba. That is because hah starts out with quality cotton and alpha paper in the beginning and oba is added in small amounts to the paper when it is made not added later when the receptor coating is put on, as is done in many of the junk papers by Red River, Epson etc.

Now as to oba not being a problem in gelatin silver papers that simply isn't true. Ask Mark about that. His tests of the modern Ilford analogue papers showed them failing miserably in the white point. I've mentioned before that a collector friend of mine owns two 20x24 ansel adams prints made from two of his most popular negatives in the late 50s to early 60's and the paper base of both of them has greyed out so much that it is just embarrassing for anyone who might want to own these as an investment. These prints hung in a condo with moderate indirect daylight hitting them for 25 years.That lowers the contrast of the whole print and Ansel  would not be amused. My own Ilford Gallerie prints from the 70's also have darkened paper base now and they were in dark storage.  With the Ilford paper being made now the paper they start with could be of even lower quality and the brightness faked even more with brightening dyes. Really these days the only way to guarantee silver papers of lasting quality is to make your own. I'm considering that when I start the alternative process work next month - printing from the Ohp film.

Contrary to my experience. I just now re-examined envelopes of prints made in 1970 (47 years ago) on a range of Agfa Portriga and Brovira papers, the Brovira BN no doubt containing OBAs . No such issues. The paper looks fine and so do the prints. Dark storage however.
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RenMar805

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Re: What happened to Wilhelm , did he die or something.
« Reply #22 on: May 22, 2017, 11:33:10 pm »

...If the major vendors of ink jet printers and inks want to slow things down, it's not difficult to do (I have no knowledge of whether this has or has not occurred).

Hi Alan:

Thanks for weighing in and sharing your experience serving on an ANSI technical group. It seems logical and fairly obvious that paper, printer and ink manufacturers would push back against any new test methodology that results in less 'favorable' print permanence data, no matter how much science screams out for such change.

Any such test modifications would likely cause alarm and confusion among consumers, who are accustomed to the ease and convenience of a simplistic 'years on display' rating based on a single light level assumption, something manufacturers are trying to avoid. It's a ratings game, pure and simple. But the longer this decades-old testing model is allowed to continue, the harder it will be to reeducate the public.

It should concern any printmaker that densitometry fails to properly measure the light colorants, multiple levels of black, reds, oranges, blues, and greens present in today's complex inksets. It fails to measure tonal loss. In addition, densitometry cannot adequately measure the impact of OBAs. Employing a methodology developed decades ago to rate chromogenic dye prints (with CMY) is simply inadequate today.   

My understanding is that this ratings game has caused the lack of manufacturer consensus, and has been the main obstacle in moving forward with more modern and appropriate test methodologies. Until there is a public outcry and pressure is put on manufacturers for more stringent test methods, things will stay the same.

You may recall this same type of stumbling block years ago with Kodak, as their standard home display illumination level assumption was 120 lux, far less than the 450-500 lux used by all other paper, ink, and printer manufacturers. Kodak was the stubborn outlier for obvious reasons, as the much lower illumination level assumption resulted in Kodak's greatly enhanced longevity numbers compared to the competition. This battle continued for a long time.

There is no real scientific basis for manufacturers to reject the I* metric model, as it's been thoroughly tested for years. To my knowledge, Aardenburg offers the only test results which both numerically and visually document color and tonal changes. 

So we can only assume politics has reared its ugly head yet again, without regard to what's best for the printing community.

Thanks again for weighing in.



« Last Edit: May 23, 2017, 12:36:13 am by RenMar805 »
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Renee M. Besta

RenMar805

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Re: What happened to Wilhelm , did he die or something.
« Reply #23 on: May 23, 2017, 12:20:54 am »

...The big thing for me that simply makes no sense is how Wilhelm gives these great figures to media that is loaded with dye brighteners.

...As an example I looked at various papers under my black light last night and watched the Canson RC media glow exactly like plain typing paper that is full of brighteners. Yet the Canson Pro Glossy RC is rated in the multiple hundreds of years with the HP inks, the same rating as Canson Rag Photo, a 100% cotton media with no OBA. Now you know that's just wrong.

In perusing numerous WIR test reports over the years, it puzzled me that papers with the highest amounts of optical brightening agents seemed to fare the best in 'permanence' ratings. Such as Epson's Exhibition Fiber paper. Or Enhanced Matte.

As many people know, the weakest or most 'fugitive' pigment ink has always been yellow. My understanding is that the reason papers with OBAs fare better than their non-OBA counterparts in WIR permanence tests is because, as the OBAs burn out and the papers return to their more natural warm state, the fading of the yellow ink is compensated for as the paper yellowing (or loss of blue) increases. So this phenomena totally skews the data.

Yes, RC papers have OBAs, as they contain titanium dioxide. But there are other problems with OBAs. Here's a great article on Aardenburg which explains them:

http://www.aardenburg-imaging.com/optical-brighteners-obas/

 
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Renee M. Besta

Ernst Dinkla

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Re: What happened to Wilhelm , did he die or something.
« Reply #24 on: May 23, 2017, 05:21:02 am »

In perusing numerous WIR test reports over the years, it puzzled me that papers with the highest amounts of optical brightening agents seemed to fare the best in 'permanence' ratings. Such as Epson's Exhibition Fiber paper. Or Enhanced Matte.

As many people know, the weakest or most 'fugitive' pigment ink has always been yellow. My understanding is that the reason papers with OBAs fare better than their non-OBA counterparts in WIR permanence tests is because, as the OBAs burn out and the papers return to their more natural warm state, the fading of the yellow ink is compensated for as the paper yellowing (or loss of blue) increases. So this phenomena totally skews the data.

Yes, RC papers have OBAs, as they contain titanium dioxide. But there are other problems with OBAs. Here's a great article on Aardenburg which explains them:

http://www.aardenburg-imaging.com/optical-brighteners-obas/


Without measurements on the paper white itself the yellow ink fading could compensate for the OBA degradation in WIR tests but I doubt it is a 1:1 compensation as OBAs tend to differ in the way they shift color in time.  The weakness of yellow ink is mainly found in Epson ink sets but their latest pigment ink. AFAIK what I recall of WIR tests of the Hahnemühle papers without OBA and with slight amounts of OBA PhotoRag, German Etching, came out better than the Photorag Bright White that has more OBA. That is within one group of papers. I have no recollection of RC papers measured then but most of them contain OBAs and depending where they are located the paper white color shift can vary a lot. If within the PE barriers of the paper base their gas fading at least is reduced. That effect also applies to the silver halide RC papers of the past and that kind of papers also has a gelatine/PVA emulsion layer that can act as a barrier to gas, oxygen, ozon, too. Which might explain that archived silver halide prints keep their fluorescence properties more or less.

"Return to their more warm natural state" is not always the case. The Epson Exhibition Fibre OBAs seem to add their own color of degradation in time. Check Aardenburg tests. There is also the effect of OBA papers stored after display that become darker in the archive and can be revived a bit by exposure to light again but degrade as well over time. Mark McCormick is the one to explain that in detail.

TiO2 whitening agent pigment has no fluorescence within the visible light spectrum. It transforms UV light to heat beyond the infra red spectrum. In that sense it can compete with OBA dyes on UV light absorption (though wave lengths can differ) but that is all. How TiO2 acts on the degradation of OBAs when mixed together is another thing, I think it might as TiO2 is used in more inventions these days to auto clean surfaces like window glass. The TiO2 whitening agents in the front PE barrier of analogue papers used to be an issue in the past, the PE degraded fast. Changes in the PE polymer and other crystalline TiO2 whitening agents have changed that effect. To get the highest OBA effect some inkjet paper manufacturers put the OBA near the front surface in the inkjet paper, exposed to all the degrading factors in print display. With TiO2 deeper into the paper structure there is no competition on UV then and TiO2 opaqueness is less of a problem too. Based on this Baryte BaSO4 is the better whitening agents in combination with OBAs, it has no UV absorption. The OBA dyes will degrade nevertheless.
https://www.ncsu.edu/bioresources/BioRes_07/BioRes_07_2_2582_Liu_SNYZZ_Review_of_OBA_Prodn_HYP_Paper_2618.pdf

Some of the latest Epson matte art papers with OBA effect seem to have a better composition or better OBA type if we check the Aardenburg Imaging test result of them.

The Epson Proofing White Semi Matte RC paper has little OBA content, there a few other RC papers among the proofing papers that have less OBA content but none have the high white reflectance and straight white reflectance spectral plot that this paper has. High gamut also due to a good inkjet coating. Weight is good. Warm paper though and not everyone will like its surface.

An older thread here on the same subject:
http://lula.brainwebhosting.com/forum/index.php?topic=96331.0

BTW, the Aardenburg article is excellent, nothing wrong with the explanation there.


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots
« Last Edit: May 23, 2017, 05:26:38 am by Ernst Dinkla »
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mearussi

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Re: What happened to Wilhelm , did he die or something.
« Reply #25 on: May 23, 2017, 07:49:23 pm »

My understanding is that TiO2 creates ozone on exposure to UV light. This becomes a problem once the print containing it is sealed in a glass protected frame. In such a sealed environment the ozone builds up and starts to attack the print. This is why I don't consider RC papers archival.
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Ernst Dinkla

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Re: What happened to Wilhelm , did he die or something.
« Reply #26 on: May 24, 2017, 04:14:27 am »

My understanding is that TiO2 creates ozone on exposure to UV light. This becomes a problem once the print containing it is sealed in a glass protected frame. In such a sealed environment the ozone builds up and starts to attack the print. This is why I don't consider RC papers archival.

If that is the case in practice then you should worry about any inkjet paper oand actually more about non-RC papers. It is a whitening agent that can and is used in anything that needs a white color. Without any specific information on the whitening agents in papers it could be present in baryta papers too. Best information on a baryta paper I have seen was the Sihl Satin Baryta paper with a 25% baryta spec. Nothing further whether that was a percentage of the total weight (unlikely) or of the whitening components used. The rest could be anything like TiO2, Kaolin, Zinc oxydes.

The process needs UV light and NOx present to create ozone efficiently. I would not worry about that in a glass protected frame. The TiO2 has to have specific properties for that too. And the TiO2 exposed to the NOx, it is usually in the paper base between the PE barriers and in a special form in the front PE barrier, anti-oxidants added there too. You would not want NOx to be in that frame anyway.
http://pubs.acs.org/doi/abs/10.1021/ja1018755?journalCode=jacsat

Edit; there is some information on that in Wilhelm's book. Describing the knowledge at that moment and the RC analogue media of the 1970s. page 581

Edit2; Wilhelm mentions the creation of oxidants due to TiO2 + UV and visible light in RC papers of the 1970-1980 period and that becoming problematic when framed behind glass. There were other conditions mentioned too like changing temperatures and humidity. Resulted in silver oxide stains in B&W papers and PE cracking, chromogene dyes in color prints also affected. As I have written before the RC papers have changed since and whether inkjet pigment inks on RC paper suffer in the same way is not tested to my knowledge. Inkjet papers in general have not been tested on degradation of mechanical aspects like the bond of the inkjet coating to the paper base.


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots
« Last Edit: May 24, 2017, 09:26:58 am by Ernst Dinkla »
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Alan Goldhammer

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Re: What happened to Wilhelm , did he die or something.
« Reply #27 on: May 24, 2017, 08:07:52 am »

The process needs UV light and NOx present to create ozone efficiently. I would not worry about that in a glass protected frame. The TiO2 has to have specific properties for that too. And the TiO2 exposed to the NOx, it is usually in the paper base between the PE barriers and in a special form in the front PE barrier, anti-oxidants added there too. You would not want NOx to be in that frame anyway.
http://pubs.acs.org/doi/abs/10.1021/ja1018755?journalCode=jacsat

Unfortunately, I don't have a subscription to the journal and can only read the abstract.  I would be interested to know what the threshold concentration of NOx is to observe this effect.  It may be a minimal concern in most indoor viewing situations.  However, were one to display images outdoors near a busy roadway the impact of NOx would be noticeable.
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Ernst Dinkla

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Re: What happened to Wilhelm , did he die or something.
« Reply #28 on: May 24, 2017, 10:14:42 am »

Unfortunately, I don't have a subscription to the journal and can only read the abstract.  I would be interested to know what the threshold concentration of NOx is to observe this effect.  It may be a minimal concern in most indoor viewing situations.  However, were one to display images outdoors near a busy roadway the impact of NOx would be noticeable.

I do not have the subscription either. It was to illustrate what the effect is. Whether NOx is needed to produce oxidants with TiO2 is another matter, I edited the message before this one.

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots
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deanwork

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Re: What happened to Wilhelm , did he die or something.
« Reply #29 on: May 24, 2017, 12:35:47 pm »

Or if you happen to show your work in Beijing.


It may be a minimal concern in most indoor viewing situations.  However, were one to display images outdoors near a busy roadway the impact of NOx would be noticeable.
[/quote]
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Farmer

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Re: What happened to Wilhelm , did he die or something.
« Reply #30 on: May 24, 2017, 06:30:40 pm »

It may be a minimal concern in most indoor viewing situations.  However, were one to display images outdoors near a busy roadway the impact of NOx would be noticeable.

In which case you really should be looking at solvent or latex / resin on a more suitable substrate, unless you just want it for very short term display.  Even then, expectations on life of the product is at best a few years.
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Phil Brown
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