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MHMG

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« Reply #20 on: September 22, 2009, 10:28:16 pm »

Quote from: Colorwave
My UV light has proven quite informative in terms of evaluating the degree of OBA brightening present (at least on the top layers).  Some papers and canvases look like they were plugged into their own light source when thy have UV to excite them.

Yes, I heartily recommend a UV black light as a serious paper evaluation tool, that and a colorimeter (UV not excluded) for paper studies.  After a while, one can really learn to differentiate concentration and coating location differences of OBAs. Believe it or not, I use a 48" UV lamp that fits a T8 or T12 fluorescent lamp fixture. Inexpensive (under $20) and "lights" up a whole work surface.

best,

Mark
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deanwork

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« Reply #21 on: September 23, 2009, 02:44:06 pm »

Jimmy,

I wasn't going to even think of bothering you about his issue, married boy. You've done far enough for us, and it's not your baby to deal with. There is an HP guy who is working on this -  a whole group of them I think. They are going to replace my Pro Satin (and hopefullly all the tons of wasted ink!) He is still trying to identify if there are indeed any good rolls out there at all. I suspect from Doug's very recent experience with files just like mine that there are good rolls and bad rolls in circulation. The problem in identifying this is that it only shows up for the most part with black and darker colored backgrounds. So, most people using it for other subjects, that don't have large smooth areas in the middle of the 44" roll, wouldn't notice it. What is disturbing is that this exact same location of the 44" roll being coated poorly was well described here two years ago and, either nothing has changed in production, OR there are tons of 2 years old rolls being sold, which I sincerely doubt. I hit three bad ones out of three in a row. The one before that was good.

In the permanence area, if you guys are at all interested in finding out more about Mark's valuable research into all this PLEASE visit and join his site. This is going to tell us a lot about inks AND MEDIA. Wilhelm tells us almost nothing really about media.

 -http://www.aardenburg-imaging.com/

Interestingly enough, if you check the HP Vivera chart on Wilhelm Research website under Hp Pro Satin he says there are NO oba's present. Very confusing for us consumers to say the least. The media is noticeably warmer than many similar papers.

What Mark just described about oba burnout is very disheartening, especially rating lower than the Premium Luster. Especially considering that the rolls of Premium Luster are twice as long! However, I just did a job on the Z with Premium Luster with black backgrounds (had no choice or time) and although it works, I just can't get over the buck shot texture of that stuff, even for large things.

Someone just mentioned that Lexjet is marketing an rc E Satin that works well on the Z, and there is that new Moab Lasal. Don't know where Legion gets that stuff, Ilford? Who knows where all this stuff comes from and who actually makes it and which ones come from the same factories. I'm suspicious that none of them are going to exhibit the total elimination of gloss differiental and bronzing issues the way Pro Satin does with these inks.

I also am very interested in knowing why other companies are not using non-oba whiteners like the Chromata canvas in their whiter media? I believe Marks tests of the BC canvas is going to hell us more about just how much better it is faring, if any. I'm afraid there are going to be a lot of grayish blotchy looking  rc prints floating around in galleries in 10 years. If  my clients come to hang me I'll need a witness.

j






Quote from: jdoyle1713
All I Can Say is WOW!! Few Things.. HP will replace the paper Thats a Given if you have a problem getting it replaced John Call me..Mark what an explanation..Thats deep stuff..Nice  By the way Gang.. Red Revir & breathing Color do not make papers or Canvas they simply Have a mill make it and than have it converted to there spec and label it! I guess you could call them a manufacture to a degree but they DO Not make these papers Nor does HP, Canon, Epson, Moab or for the record any Private label company..

Hope everyone is doing well I have been not participating in the last few months .. But I am back

Cheers
Jim Doyle
http://www.shadesofpaper.com
« Last Edit: September 23, 2009, 03:24:31 pm by deanwork »
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MHMG

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« Reply #22 on: September 23, 2009, 09:24:36 pm »

Quote from: deanwork
Interestingly enough, if you check the HP Vivera chart on Wilhelm Research website under Hp Pro Satin he says there are NO oba's present. Very confusing for us consumers to say the least. The media is noticeably warmer than many similar papers.

What Mark just described about oba burnout is very disheartening, especially rating lower than the Premium Luster. Especially considering that the rolls of Premium Luster are twice as long! However, I just did a job on the Z with Premium Luster with black backgrounds (had no choice or time) and although it works, I just can't get over the buck shot texture of that stuff, even for large things.

Maybe just a documentation error in the WIR report. The only OBA-free image layers on RC base I've ever seen are proofing papers and even they still have OBA in the paper core. The Pro Satin sample submitted to me definitely has OBAs in the top coat, and I wouldn't describe it as warm. It's a bright white paper for sure though not as strikingly blue as some of the "over the top" bright white papers like the Red River papers mentioned by Colorwave in this thread. The Pro Satin measured b* = -4.0 UV included, b*= +0.5 UV excluded, for a delta B* value of 4.5, i.e, significant OBA content. Although the possibility of misidentification always exists, I've also seen another sample from another batch. It was initially bright white, too, and ironically, was sent to me by a colleague as an example of a paper that had turned slightly yellow due to OBA loss in a window fade test after only about three months (less than 10 Megalux hours of exposure). My colleague didn't understand how a paper rated at 250+ years on display could discolor so quickly in a window fade test lasting only 90 days. I point out as I noted in my earlier post that the level of discoloration he observed was less than the amount that would be needed to trigger a paper white failure point in a consumer-oriented test. He was noticing (and objecting to) a change that would not be judged "easily noticeable" by an image quality-tolerant consumer, yet he and I both agreed it was both noticeable and visually significant for a fine art or professional portraiture application.

You might want to give Canon Heavyweight Satin Photographic paper a try. It will look closer in surface texture appearance to the HP Pro Satin than a luster surface paper.  I see no reason it wouldn't print well on your Z3100. And although it has OBAs as well (b*=-4.6 UV included, b* = -1.2 UV excluded, delta B* = 3.4) the Canon Heavyweight Satin took significantly higher light exposure dose to trigger the lower limit of the AaI&A Conservation Display rating with Lucia pigmented ink compared to the HP Pro Satin with Vivera pigmented ink (104 megalux hours versus 13 megalux hours), and this lower limit was reached in both cases due to paper white and highlight color changes (highlight color change caused by the underlying paper color change) not so much ink fade. The upper Conservation Display rating (a measure of overall system performance) has not yet been reached for either of these test samples. Also, members of the AaI&A digital print research program are welcome to submit samples, so this unique printer/ink/paper combination actually has a chance of getting tested by AaI&A, whereas neither Canon nor HP would ever be likely to submit this product combination for testing with other independent labs!

Lastly, for those who would like to know more about my OBA research, you can take a look at a recent paper I posted on the documents page of my website. It's entitled "Case Study #2:  A Year in the Life of an Inkjet Print – Environmental, Colorimetric, and Visual Assessments".  Perhaps a very good article to put you to sleep, but nonetheless it documents real world gas fading of OBAs among other things.  The following link should hopefully provide a free and direct download:

http://www.aardenburg-imaging.com/cgi-bin/...NDU2Nzg5LyoxMzM


cheers,

Mark

http://www.aardenburg-imaging.com
« Last Edit: September 23, 2009, 09:48:46 pm by MHMG »
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Ernst Dinkla

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« Reply #23 on: September 24, 2009, 04:34:01 am »

Quote from: MHMG
The only OBA-free image layers on RC base I've ever seen are proofing papers and even they still have OBA in the paper core. The Pro Satin sample submitted to me definitely has OBAs in the top coat, and I wouldn't describe it as warm.
cheers,

Mark

http://www.aardenburg-imaging.com


Mark,

With RC papers I often wonder what the construction differences are.

As I understand it the RC barriers at the front of the paper base have been white themselves, a TiO2 whitener quality mixed in that no longer degrades the "polyethylene" fast like it did in the early days of RC paper. If the inkjet coating didn't contain OBA and the RC barriers are transparent (including transmission of UV) like the one on the back usually is then the OBA can be used in the paper base itself. Which may need to be a more white base than used in the other versions to compensate the change from white to transparant in the front barrier.

Then there is a micro porous layer (film?) at the top of the inkjet paper, allowing the ink to penetrate but at the same time protecting a finished print. Partly causing the bronzing effect where the ink can't penetrate fast enough. Is that micro porous layer acting like a membrane and is the actual inkjet coating beneath that or is the total composition of the coating the micro porous layer ?

There are 3 layers to add OBA to. It will be most effective in the inkjet coating but it degrades faster there too. It could be added to the polyethylene barrier at the front but as I understand it the combination of TiO2 and OBA's isn't an effective one and the OBA functioning may also cause problems with the polyethylene, in itself not very UV resistant either. For gamut it could be the best spot as all the ink settled will be in front of that layer. Next is the base, starting from a white pulp base adding whitener and OBAs to get a similar effect will ask for higher doses and the total will be more expensive.


met vriendelijke groeten, Ernst Dinkla

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/
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MHMG

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« Reply #24 on: September 24, 2009, 09:01:22 am »

Quote from: Ernst Dinkla
Mark,

There are 3 layers to add OBA to. It will be most effective in the inkjet coating but it degrades faster there too. It could be added to the polyethylene barrier at the front but as I understand it the combination of TiO2 and OBA's isn't an effective one and the OBA functioning may also cause problems with the polyethylene, in itself not very UV resistant either. For gamut it could be the best spot as all the ink settled will be in front of that layer. Next is the base, starting from a white pulp base adding whitener and OBAs to get a similar effect will ask for higher doses and the total will be more expensive.

Ernst, you have described the "basic" construction of RC photos well, but RC papers, depending on whether they are designed for inkjet or for silver halide chemistry often have additional coating layers to improve product performance.  With silver halide systems, for example, there is inevitably a supercoat layer of hardened gelatin on top to impart much better abrasion and handling characteristics when the print is dry. That layer can also contain matting agents and sometimes these wonderful little spherical particles the photo industry calls "goofballs" as a slipping/anti-abrasion agent.  One can't get away with this supercoat layer design in inkjet!  

With inkjet, there is typically at least one very important additional layer between the colorant receptor layer and the PE/TiO2 layer. It's a subbing layer that performs an important task. It helps to chemically separate the colorants from the solvent and give the solvent a new place to reside.  Its porosity/solvent absorbing properties are usually and purposefully made different than the colorant receiving layer. The subbing layer's primary role is to wick away the solvent from the colorant receptor layer while attempting (usually quite successfully) to assist in keeping the colorants isolated up in the top layer for better color gamut. The subbing layer's solvent absorption rate doesn't have to work as quickly as the very top coat but it does need to work. Without this extra solvent wicking layer in the print, the solvent would stay trapped in the top surface layer. Allowing the solvent to stay trapped completely with the colorant in the top coat can have adverse affects on print permanence and also promote ongoing off-gassing that fogs up picture frame glass.  The PE layer in the RC paper base prevents the solvent from having a good diffusion pathway into the paper core, and the excess solvent then has an easier time migrating towards the picture frame glass rather than into the paper core.  Even with a good subbing layer for solvent trapping, the inability of the solvent to be sucked up into the very-thick-by-comparison paper core makes RC inket papers more prone than the non RC paper types to leaving a glycerine/glycol haze on picture frame glass. It is also why many printmakers leave considerable time for the RC print to "dry" before framing, and some even go so far as to place "blotter paper" on top of the print for a day or two to help extract solvent before it goes to the framer.  Framers that get framed inkjet prints back from the customer to clean the haze formation on the glass more often than not had framed an RC inkjet print.

As has been noted elsewhere in this thread, there are many private label vendors out there, so different brands can in fact be coming from the same manufacturing source. In fact, many of the inkjet paper manufacturers are only coaters. They buy the RC paper core in bulk and simply add the requested inkjet coatings to contract specification for the private labelers.  RC papers have been so prevalent in traditional photo finishing for the last 30 years that the RC base (complete with already existing OBAs) is produced in huge quantities, hence the very advantageous price point for RC papers.  If no more OBA is added in the additional coatings, many resellers then claim the product is OBA-free (by virtue of the fact that the OBAs aren't in the image bearing layer) when in fact there is still some OBA in the product, and that OBA does still add a little "kick" to overall media whitepoint.  Clearly, both the concentration and the location(s) where the OBAs reside in in the product have strong bearing on just how visually significant the OBA burnout will appear over time. It's why I do give general advice to avoid the super bright white Inkjet papers because it's a good bet the OBAs are heavily in the top coat and will get degraded by gas fade and light fade problems very quickly. Yet when OBAs are used with more discretion, OBA containing papers can turn in good longevity performance.  

AaI&A members can look at the UV included/UV excluded whitepoint values and the corresponding delta B* calculation provided in each test report to get a sense how dependent the media whitepoint is on OBAs.

kind regards,

Mark
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deanwork

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« Reply #25 on: September 24, 2009, 09:54:32 am »

Mark,

We've discussed this before. I think you are being very generous to suggest that WR made a typo in  not labeling Pro Satin as having oba content. There are three categories he uses, no oba, some oba, and yes ( oba).

In both the Z3100 data ( that has been up there for over a year and a half) and the new and the more recently posted Z3200 data, both are showing Pro Satin to be oba FREE. That means none. I can't imagine with the significance this presents that it could be a simple typing error. If they don't review their data any closer than THAT it is all suspect in my opinion. If you look at the top of these spread sheets though, he's protected himself legally. In parenthesis it states, "Preliminary", whatever that means.....http://www.wilhelm-research.com/hp/Z3200.html

But as you and Jon Cone have pointed out in the past, a lot of errors exist. Such as Epson Enhanced Matte receiving a bare bulb rating of 45 years. That simply is false. We see degradation of the white base in two or three years on a bulletin board with very low uv exposure or ozone exposure time and time again. Like many of the Red River papers, it simply turns gray.

John
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deanwork

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« Reply #26 on: September 24, 2009, 10:07:52 am »

It has been noted in some conservation papers that the reason that albumen papers often tarnish over time and have that strange metallic discoloration is that the gelatin that later silver coating  emulsions had was not there. The albumen simply didn't protect against oxygen in the long term ( though in book form, many of them held up quite well, but you can often see the metallic discoloration around the edges - as in Carlton Watkins giant folio of Yosomite valley done in the 1861 that we used to show in Tucson - http://www.nga.gov/exhibitions/watkinsbro.htm. However, gold toning in some cases seems to have had less of the tarnishing problem, if I remember correctly.

-----------
Ernst, you have described the "basic" construction of RC photos well, but RC papers, depending on whether they are designed for inkjet or for silver halide chemistry often have additional coating layers to improve product performance.  With silver halide systems, for example, there is inevitably a supercoat layer of hardened gelatin on top to impart much better abrasion and handling characteristics when the print is dry.
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MHMG

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« Reply #27 on: September 24, 2009, 01:53:10 pm »

Quote from: deanwork
Mark,

If you look at the top of these spread sheets though, he's protected himself legally. In parenthesis it states, "Preliminary", whatever that means.....http://www.wilhelm-research.com/hp/Z3200.html

But as you and Jon Cone have pointed out in the past, a lot of errors exist. Such as Epson Enhanced Matte receiving a bare bulb rating of 45 years. That simply is false. We see degradation of the white base in two or three years on a bulletin board with very low uv exposure or ozone exposure time and time again. Like many of the Red River papers, it simply turns gray.

John

Right. I certainly can't speak directly for WIR, but my understanding based on a longstanding friendship and collaboration with Henry Wilhelm, is that you will see "greater than" (>) signs in some of the WIR data, and the "preliminary" designation as well when a product has gone far enough in test to otherwise receive a rated score the manufacturer is satisfied to have reported (for example, "> 100 years") even though the final score hasn't been determined in test yet.  Because industry-sponsored tests are currently conducted with specific endpoint criteria to be exceeded, the use of a "preliminary" finding is really the only option available to the manufacturer (and to WIR using its present testing methodology) to get at least some information about a relatively stable product out to the public at the time of product introduction.  High stability products often take a year or more even in an accelerated test to reach final endpoint failure criteria and thus get an official score, especially when those criteria allow for significant changes to occur.

Product tweaks are sometimes occurring right up to product launch time, so it gets challenging to coordinate meaningful print longevity ratings with product introductions. If a test were to get started, then a production change occur, the test would then at best have to be a "preliminary" finding. A confirmation test would later have to be run in order to ensure that the product change didn't impact the prior testing outcome. Of course, there are other pitfalls in presenting preliminary findings as well.  For one thing, with so many "preliminary" results and tests ongoing, the reports often seem very incomplete.  In contrast to this single endpoint method of rating products, AaI&A posts light fastness test results on regular exposure intervals (10 megalux hours which is equivalent to 5 WIR years, approximately 20 Kodak years on display), so even though AaI&A tests are by their very design routinely "ongoing", there is nothing preliminary about the results that are being posted.  The reported color and tonal accuracy scores correctly relate how the product is performing at each reported exposure dose, and the end-user can then relate this performance to his/her own real world conditions.  That said, AaI&A's more comprehensive testing and reporting method also demands that AaI&A members work harder to draw their conclusions. I believe it's worth the extra effort if print permanence really matters to you.  Also, AaI& doesn't add pre-production or prototype materials to the AaI&A database. Hence, I don't face the issue of product formulation changes prior to product introduction.  But  I do have to be vigilant of commercially available products undergoing reformulation. For example, Museo Silver Rag has apparently been modified recently, so it means AaI&A members need to submit more recent samples, and AaI&A has to find thoughtful ways to identify these product reformulation timelines in its database.

This discussion on OBA burnout and subsequent yellowish/grayish appearance of the paper is a classic case and point where the industry-sponsored endpoint analysis of changes in media white point is simply too liberal to square up with a fine art printmaker's or serious collector's assessment of the onset of paper discoloration. One needs to be informed of the early stages of print deterioration in order to evaluate important differences in OBA performance, and the current industry print life ratings simply don't provide any basis for this judgement.
« Last Edit: September 24, 2009, 02:28:27 pm by MHMG »
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Ernst Dinkla

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« Reply #28 on: September 29, 2009, 05:00:37 am »

Quote from: deanwork
It has been noted in some conservation papers that the reason that albumen papers often tarnish over time and have that strange metallic discoloration is that the gelatin that later silver coating  emulsions had was not there. The albumen simply didn't protect against oxygen in the long term ( though in book form, many of them held up quite well, but you can often see the metallic discoloration around the edges - as in Carlton Watkins giant folio of Yosomite valley done in the 1861 that we used to show in Tucson - http://www.nga.gov/exhibitions/watkinsbro.htm. However, gold toning in some cases seems to have had less of the tarnishing problem, if I remember correctly.


John,

The combination heavy metals and gelatine is the forte of "analogue" B&W photography. The gelatine protecting the metal, the metal hardening the gelatine and acting as a biocide. Probably just luck that the two selected for other properties had that interaction too. Of course more archival processes improve on that resistance but a good darkroom practice with the normal ingredients already delivered very good aging resistance.

My curiosity in this thread is whether the RC barriers reduce the oxidation of the OBA dyes like a gelatine layer protects dyes better. Depending on the layer the OBAs are in there should be differences in their degradation. Another question is whether the HP gloss enhancer (most likely a PVA) does anything like a good gelatine coating should. Depends a lot on the hydrolyses grade of the PVA and gelatine I guess, influencing oxygen/water permeability. If I recall it correctly in fruit drink packaging polyethylene combined with PVA coatings hold the fluids and block oxigens.

I can not find a report of different papers and dye/pigment inks published in a German magazine (most likely done by Image Engineering) where the RC papers showed a good protection against gas fading of dyes if compared to non-RC papers. The dye prints still inferior to pigment prints on light resistance but interesting to notice that aspect. I have to find that again to see what papers were compared.

Mark mentions the proof papers with OBA only in the paper base, between the PE layers. Could be an alternative too.

Epson EEM matte (non RC) was mentioned in the thread. I use it too and noticed the yellow/grey shift (it is already more yellow at the back when fresh). I will switch to the HP Litho Realistic which is less white when fresh if my HP swatch book tells the truth. More like the EEM back or Photorag front and heavier in weight. Anyone who uses that? Price is similar to the EEM here but 36" is the widest available. I noticed that the roll of HP HM Smooth Fine Art Paper white is also warmer than the Photorag rolls I have. More than the differences between Photorag batches. As much a difference between HP HM SF <> Photorag as there is between Photorag <> Photorag Br. Wh.


met vriendelijke groeten, Ernst Dinkla

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/






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MHMG

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« Reply #29 on: September 29, 2009, 08:36:35 am »

Quote from: Ernst Dinkla
My curiosity in this thread is whether the RC barriers reduce the oxidation of the OBA dyes like a gelatine layer protects dyes better. Depending on the layer the OBAs are in there should be differences in their degradation. Another question is whether the HP gloss enhancer (most likely a PVA) does anything like a good gelatine coating should. Depends a lot on the hydrolyses grade of the PVA and gelatine I guess, influencing oxygen/water permeability. If I recall it correctly in fruit drink packaging polyethylene combined with PVA coatings hold the fluids and block oxigens.


The report on my website to which I provided a link (free download) earlier in this thread actually shows evidence of a GLOP layer retarding the ozone degradation of the OBA. The print was made on a glossy microporous paper with an Epson R1800 and The GLOP feature was used.  The GLOP stopped about 3 mm from the edge of the paper, and the subsequent gas fading of the OBAs did reveal this GlOP/no GLOP line of demarkation. I show a photo made under blacklight in this report that clearly reveals this GLOP/OBA passivation effect.  That said, for any plastic coating to provide significant barrier properties (whether it be UV, moisture, or gas barrier benefits) it must be several microns thick, and even thicker is better. So, the GLOP layers are simply too thin to provide a longer term solution to OBA degradation caused by ozone and moisture. Likewise, claims of significant UV protection and moisture proofing by various post coatings only work when the coating is thick enough that the aesthetic texture/surface properties of the coated versus uncoated print are very obvious. "Varnishes" that are thin enough to preserve most of the original paper texture can add some gloss, enhanced color gamut, and reduce bronzing/gloss differential effects, but they won't be thick enough to offer serious long term gas and moisture protection.  Even the very best plastics are still quite permeable when they are less than a few microns thick.

As Ernst has also noted, the location and concentration of the OBAs within the product's multi layer construction, have a big impact on the subsequent media whitepoint discoloration caused by OBA degradation. However, as I've also noted earlier, the industry-sponsored light fade and gas fade tests allow too big a white point shift such that OBA degradation, although easily noticeable to relatively discriminating end-users, does not trigger any of the test endpoints.  OBA degradation gets a free pass in these display life predictions.  AFAIK, the only available print permanence testing method that gives any indication of loss of OBA activity and its impact on image appearance is on the AaI&A website.

One last observation about traditional photos that also has some bearing on inkjet media technology. The gelatin layers used in traditional photographs are indeed thick enough to seal the image bearing silver or dyes quite well... provided that the gelatin remains dry. Relative humidity above 75% (a very real world phenomenon in many parts of the world) at human comfort zone temperatures (e.g., 21 deg. C) will enable gelatin to cross its glass transition temperature (Tg) and revert to gel state. It then quickly loses its vapor barrier properties until it later returns again to the dry state. When you see old B&W photos that exhibit "silver mirroring" this silver tarnish occurred during periods when the print was exposed to temperature/humidity conditions that allowed the glass transition temperature of the gelatin to be exceeded. The silver particles oxidize, the silver ions then are free to diffuse through the gelatin layer in its gel state, and they are then later reduced on the surface of the gelatin as a thin metallic layer that causes the metallic sheen on the print.  Ferrotyping of photographs to glass (i.e, when the print sticks to picture glazing and can pick up an unwanted glossiness as well) is also a direct consequence of gelatin crossing its Tg.

The material properties of plastics are really interesting!

cheers,

Mark
http://www.aardenburg-imaging.com
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