Luminous Landscape Forum

Raw & Post Processing, Printing => Printing: Printers, Papers and Inks => Topic started by: enduser on March 30, 2018, 01:39:17 am

Title: Choosing the right paper
Post by: enduser on March 30, 2018, 01:39:17 am
I've noticed for a given printer and ink combination results can generally vary depending on the paper.  Do we know the makeup of the papers that generally give the best results?  How important for image quality is the actual paper base, middle and top layer? And of course, are papers that are good for Epson, also good for HP and Canon?
Impressions might be of some help but definitive research would be most useful. On the other hand someone who knows could say "Well, it's all about the thickness/quality of materials/manufacturing tolerances/etc... "  I certainly don't know.
Title: Re: Choosing the right paper
Post by: Mark D Segal on March 30, 2018, 07:59:07 am
I've noticed for a given printer and ink combination results can generally vary depending on the paper.  Do we know the makeup of the papers that generally give the best results?  How important for image quality is the actual paper base, middle and top layer? And of course, are papers that are good for Epson, also good for HP and Canon?
Impressions might be of some help but definitive research would be most useful. On the other hand someone who knows could say "Well, it's all about the thickness/quality of materials/manufacturing tolerances/etc... "  I certainly don't know.

I'm having some trouble envisioning what you are trying to find out about because the items of interest to you are not defined. This comment isn't meant to be critical - I'm trying to help by indicating we need clarity in the questions to be able to answer in ways that will be most useful to you. For example,

(i) when you say "results can vary" - well you're right of course, a number of characteristics not only can vary, they do. But what aspects of "results" are you concerned with?
(ii) "make up of the papers that give the best results" : what attributes define "best results"?
(iii) "How important for image quality": again, what attributes of image quality?
(iv) "papers good for Epson.....": means "good" in what respects?
(v) "definitive research": research into what, and what do you mean by "definitive"?
(vi) "it's all about": what is the "it's"?

You started what could be a useful thread, but the way this is framed I expect the conversation to be loose and all over the place. Perhaps you could add some precision right from the get-go?
Title: Re: Choosing the right paper
Post by: Alan Goldhammer on March 30, 2018, 08:47:45 am
IMO, the best thing to do is pick a couple of your best images for testing.  Most paper manufacturers sell trial size packs of different papers.  Print your image(s) on the papers and see what appeals to you as paper choice is incredibly subjective.  Of course you will have to rely on the manufacturer's profile in the case of color prints but that's OK, you are doing this as a first cut to narrow down the choice.  If you feel a custom profile is a worthy investment you can DIY or find a provider to do it for you.  I have found that it's easy to get trapped in to testing lots of papers and for me it's better to settle on 3-5 papers just to keep my sanity.  In no order of preference I currently print on:

Hahnemuhle Photo Rag Ultra Smooth & Bamboo
Moab Entrada Natural & Somerset Museum Rag
Museo Silver Rag

I'm still partial to matte papers, but others are not.  That's OK in this world of choice. 
Title: Re: Choosing the right paper
Post by: enduser on March 30, 2018, 08:52:02 am
Thanks, Mark - good points. The way I began this thread is  probably because of the unquantifiable personal likes and dislikes that will color people's opinions about papers. Clearly we all know gloss from matte etc.  What I am interested in is how the actual paper make-up affects image quality.  I hear terms like "cotton", "cellulose" and others,  but as to how this affects the end result, I'm not sure.
Perhaps the optical brighteners effects are more easily understood, but terms such as "deinked pulp" and "chemical pulp" mean little to me. Wikipedia gives a pretty good review of the possible materials in an inkjet paper. What I am hoping for is someone's opinions of what materials make the best image.
Title: Re: Choosing the right paper
Post by: Mark D Segal on March 30, 2018, 09:06:20 am
Yes, unquantifiable I can understand - not everything can be quantified; but all the aspects of papers that concern you are amenable to articulation - that's what I was hoping to see. The response you got from Alan is the kind of discussion I expected - a very knowledgeable contributor's perspective on what you may do to makes choices, and what he likes, which is all fine and respectable, but does that really answer your questions?

As you know, I've done lots of paper and printer reviews for this website. There are important performance characteristics that can be quantified, and where it makes sense I have tried to do so in an approachable manner. More will be coming, by the way. So those reviews deal with some matters but not others. Wilhelm and Aardenburg quantify important issues about longevity. Ernst Dinkla provides valuable quantified data on spectral response. Ethan Hansen has contributed important quantified insight into the construction of quality profiles. But once we leave the quantifiable, we are into taste and judgment calls. Those can be discussed qualitatively, but they still require conceptual articulation, especially absent quantification. Then there can be a useful discussion addressing your concerns.
Title: Re: Choosing the right paper
Post by: stockjock on March 30, 2018, 02:08:43 pm
I've noticed for a given printer and ink combination results can generally vary depending on the paper.  Do we know the makeup of the papers that generally give the best results?  How important for image quality is the actual paper base, middle and top layer? And of course, are papers that are good for Epson, also good for HP and Canon?
Impressions might be of some help but definitive research would be most useful. On the other hand someone who knows could say "Well, it's all about the thickness/quality of materials/manufacturing tolerances/etc... "  I certainly don't know.

Unfortunately, there are so many variations not only between printers, papers, and profiles but also individual preferences that "best" really has no meaning in this context.  Gamut, longevity, and spectral response (OBA's) are all important quantitative measurements of a paper/printer/profile combination but they don't include other characteristics like hand feel, thickness, sheen/surface that might be much more important to you.

I have standardized most of my printing on the Canson Platine and Rag Photographique (and the Epson equivalents) with some specialty prints on the Epson Metallic Gloss.  The Canson papers are relatively affordable and offer a good combination of the factors that have been important to me.  But recently John Nollendorfs recommended a paper on here called HP Everyday Pigment Ink Satin Photo Paper which is only available on rolls.  This is probably the cheapest paper you can find and it is very thin and flimsy but I have been astonished at the quality of the prints I've gotten with my iPF8400 using the canned Canon Satin 240gsm media type and profile.  So what is the "best" paper?

When I first started printing I was frustrated with the knowledgeable posters on here refusing to answer the question about what the "best" papers were but as I have acquired more experience I have come to understand that not only does the question have no answer but no answer is possible given how much individual preference matters.  Even if there were a perfect paper with the widest gamut, best longevity, least amount of OBA', and most attractive pricing there would still be subjective questions about hand feel, surface, sheen and the general character of the paper that would vary from user to user and even image to image.
Title: Re: Choosing the right paper
Post by: Miles on March 30, 2018, 04:39:02 pm
As far as trying out papers, I don't think it matters who the manufacturer is.  More important is getting the correct profile for the paper being used.  I believe you have a Canon printer, thus you probably have Canon profiles already loaded for their papers.  Most companies will have profiles you can download to try out their papers, or you can get a color munki and make your own.  Another option is to decide on a paper you like and have someone custom build a profile for you.  I think digital dog provides that service as well as many others.

To me, sample packs have a limited value because you only get a sheet or two of each type to try.  It can be hard to draw a conclusion from one print, especially with a new profile.  Breathing Color does offer some short rolls at reasonable prices and I find this gives more of an opportunity for proper testing.  Is it OK to admit I like trying out new papers once in a while? :)

I watched this forum to see what people like and then sought out the papers that I felt my fit my needs in the price range I want to pay.  I especially like Breathing Color Lyve canvas and Canson Plantine paper.  I have tried sample rolls of many of the Breathing Color products and like the output, but do not have that much need for them.  Epson luster also has a nice look and I sometimes will use Kodak luster, but I don't find that much difference in the RC papers. 

Good luck in your quest.

Miles

 
Title: Re: Choosing the right paper
Post by: Alan Goldhammer on March 31, 2018, 11:17:30 am
What I am interested in is how the actual paper make-up affects image quality.  I hear terms like "cotton", "cellulose" and others,  but as to how this affects the end result, I'm not sure.
Perhaps the optical brighteners effects are more easily understood, but terms such as "deinked pulp" and "chemical pulp" mean little to me. Wikipedia gives a pretty good review of the possible materials in an inkjet paper. What I am hoping for is someone's opinions of what materials make the best image.
The paper material is close to irrelevant if that is the question you are asking.  Photo papers are derived from plant sources and the primary constituent is alpha-cellulose.  It is important during the paper making process that lignin, a structural component, is eliminated as it can cause yellowing of the paper (it's present in high quantities in newsprint).  This can be accomplished by either using plant materials with low starting lignin concentrations (cotton fibers) or eliminating lignin during the pulping process.  Photo papers can be advertised as being made from cotton rag or as alpha-cellulose but it doesn't matter as both papers are close to identical in terms of there structure.  The only issue of interest here is the tactile feel of the paper.  Some papers also have a polyethylene (I'm pretty sure this is the plastic used) coating which gives the paper a stiff feel that is not "paper" like.

There are two things that govern the image that you print:  the coating that is applied to the paper and the underlying warmth of the paper stock.  In addtion additives such as optical brightening agents or Barium Sulfate (baryta) are sometimes added to the paper to improve the brightness of the paper.

I hope this addresses the OP's question.
Title: Re: Choosing the right paper
Post by: Mark D Segal on March 31, 2018, 01:16:56 pm
Very useful information Alan.

On the use of OBAs, I would only add that according to a Hahnemuhle rep with who I once discussed this, where the OBA sits in the paper will make a difference to how it deteriorates. He was saying that Hahn puts it into the substrate, whereas there are other manufacturers who put it into the coating, and the former will cause far less deterioration over time. I'm sure Mark McC-G would have a view on that.
Title: Re: Choosing the right paper
Post by: Alan Goldhammer on March 31, 2018, 01:33:07 pm
Very useful information Alan.

On the use of OBAs, I would only add that according to a Hahnemuhle rep with who I once discussed this, where the OBA sits in the paper will make a difference to how it deteriorates. He was saying that Hahn puts it into the substrate, whereas there are other manufacturers who put it into the coating, and the former will cause far less deterioration over time. I'm sure Mark McC-G would have a view on that.
That is correct regading OBAs.  You can also see the difference on Ernst Dikla's spectral analyses.  Hahnemuhle Photo Rag Ultra Smooth has a small amount of OBA in the paper and the Aardenburg results from my Epson 3880 samples show pretty decent stability in those studies.
Title: Re: Choosing the right paper
Post by: enduser on March 31, 2018, 09:39:54 pm
Let me re-phrase my first question.  If I look at Ardenberg results (What an amazing resource) for a given printer and ink combination I will see that of two different papers there might be significant differences between the i*tone (worst 10%) at 140 Megalux hours.

Why the difference? The only variable between tests is the paper. Is it the thickness, the coating, is the silica precipitated, fumed or colloidal, (Got that out of a book!) kaolin (clay), starch etc etc.? On researching the topic, it seems there may be 20 or so components in inkjet papers and not all papers are the same formula.

So my quest is to find out which, if any, of the manufacturing variations has any bearing on image quality.

Title: Re: Choosing the right paper
Post by: Mark D Segal on March 31, 2018, 10:25:04 pm
If you could define specifically what you mean by "image quality" perhaps this thread can begin to make some headway.
Title: Re: Choosing the right paper
Post by: enduser on March 31, 2018, 11:22:12 pm
Image quality might be a bit personal between photographers.  Let's list a few things though. Ink fading overall, paper disintegration, ink fading differential between colors, ink adherance, reflectivity between full gloss papers, reality of color in a fully color managed system - that is, no weak colors or over saturation. I could go on, and some of the things mentioned are in the operators hands too.
But, are any of these affected by paper composition and/or manufacturing methods (or voodoo within the factory). I can't define my inquiry with anything more succinct.
Title: Re: Choosing the right paper
Post by: nirpat89 on March 31, 2018, 11:52:42 pm
Image quality might be a bit personal between photographers.  Let's list a few things though. Ink fading overall, paper disintegration, ink fading differential between colors, ink adherance, reflectivity between full gloss papers, reality of color in a fully color managed system - that is, no weak colors or over saturation. I could go on, and some of the things mentioned are in the operators hands too.
But, are any of these affected by paper composition and/or manufacturing methods (or voodoo within the factory). I can't define my inquiry with anything more succinct.

It's complicated!
Title: Re: Choosing the right paper
Post by: Mark D Segal on April 01, 2018, 09:56:35 am
Image quality might be a bit personal between photographers.  Let's list a few things though. Ink fading overall, paper disintegration, ink fading differential between colors, ink adherance, reflectivity between full gloss papers, reality of color in a fully color managed system - that is, no weak colors or over saturation. I could go on, and some of the things mentioned are in the operators hands too.
But, are any of these affected by paper composition and/or manufacturing methods (or voodoo within the factory). I can't define my inquiry with anything more succinct.

OK, that's a good start. Now we have something to talk about. For fading, please check the website of Aardenburg Institute and Wilhelm-Research. Those are the two main sources for information on print longevity. Ink adherence - don't worry about it, not an issue. Reflectivity is best seen from the gamut volumes and Maximum Black data. You get that from detailed paper reviews, such as the many of mine published on this website. The quality of colour reproduction depends most importantly on the quality of your color management set-up, not the paper - except that with gloss/luster papers you have wider gamut and deeper blacks than with matte paper, so that will affect vibrancy of colour reproduction. Not that one is good or not good. Different kind of paper suit different images - that's a matter of artistic judgment, not the manufacturing of the paper. Apart from the major gamut/maximum black differences between papers, which depend on the coating and surface texture (you can read about in the more detailed paper reviews), most of image quality is in the hands of the photographer/printer.
Title: Re: Choosing the right paper
Post by: enduser on April 02, 2018, 10:00:26 pm
Mark, you mention fading, something of concern for just about everyone.  When you see that one (eg a matte paper), is better than another, given all else is equal as measured at Ardenberg, don't you ask yourself why? We've seen a lot of good discussion about OBAs but there's a lot more to a paper than that.

(When I use "all else is equal" I mean same inks, same printer, same expert operator and marked as premium photo matte.)
Title: Re: Choosing the right paper
Post by: Mark D Segal on April 02, 2018, 10:27:46 pm
Mark, you mention fading, something of concern for just about everyone.  When you see that one (eg a matte paper), is better than another, given all else is equal as measured at Ardenberg, don't you ask yourself why? We've seen a lot of good discussion about OBAs but there's a lot more to a paper than that.

(When I use "all else is equal" I mean same inks, same printer, same expert operator and marked as premium photo matte.)

Nope - I don't need to know why. I'm not a papers chemist and it's not a priority interest. I'm interested in the results - will the paper resist fading for 20 years or 100 years in the conditions in which I'll be storing it? That's worthwhile knowing. You're right OBAs isn't everything. OBAs can fade over time and the way in which they fade can make the print quite ugly or not, depending on a number of factors. Other than that, the longevity of specific inks on specific papers is a more important issue to my mind, so I do look at those results with interest, but again, not for me to get much into why.
Title: Re: Choosing the right paper
Post by: mearussi on April 03, 2018, 02:01:26 am
You've gotten a lot of generalities here so I thought I'd add a few specifics.

1. There are only a few professional quality paper makers in the world and most (if not all) of the inkjet paper manufacturers buy from them and then have their propriety coatings added later by a coating company. For instance, Hahnemuhle and Canson have been making paper for centuries so many other inkjet paper companies (Moab, Breathing Color, Red River, Innova Art, etc.) could easily be selling Hahnemuhle or Canson paper but with their own specific coatings on it. But even Hahnemuhle and Canson have someone else coat their papers for them.

2. There are only a few paper base combinations available, such as cheap paper with a plastic over coating on both sides, commonly known as RC (resin coated). These RC papers include the ever popular economical glossy, satin and luster papers used in photo labs worldwide, but also sold by all pro inkjet paper manufacturers as well (everyone wants a cheap line). These universally contain OBAs to add an extra color punch.

The two other main papers are 100% Cotton "rag" and Alpha-Cellulose, whose primary difference is their source, the first from cotton, the second from wood pulp in which all the lignin has been removed (lignin will eventually decay and produce acid byproducts so its removal is essential for anything to be considered archival). They are both acid free and considered "archival" which itself is a undefined term and is used primarily for marketing purposes. Their only noticeable difference is in their texture, the cotton being softer and more flexible whereas the Alpha-Cellulose is stiffer and more like poster board. I prefer the cotton because of feel, but functionally they are the same. Variants can also include whether they have any added alkaline buffering agents such as calcium carbonate to help neutralize airborne acid gasses, which further adds to their long term stability. These may or may not contain varying amounts of OBAs depending on what the company wants.

3. Lastly are all the specialty papers made from bamboo and other exotic materials each with their own unique look which, unless you have a specific need for them, can easily be ignored. But the one "paper" you may want not want to ignore is actually made from polyester and is usually called "white film" or sometimes is designated as "superglossy."

This polyester substrate has some very useful qualities like having a perfectly smooth surface so there's no paper texture to interfere with the finest detail as there is in all other papers. It's also totally resistant to any environmental conditions (except fire, of course) especially water and/or high humidity environments that could cause all other papers to warp, swell or mold. This is the same material that the old Cibachrome and Fuji Superglossy was (and still is) made from. It produces its own unique look unmatched by anything else except the new metal printing process. It's also the only roll paper that has virtually no curl and that will hang almost perfectly flat in a frame without being dry mounted (which can save you both time and money). It is a little more expensive than the best cotton papers but for me it's worth it for all the reasons listed above. I've printed some very beautiful photos with it but quit using it when Ilford went bankrupt, as I was using their version and have not yet got around to testing other companies (Mitsubishi, Canon) versions of it.  It also contains OBAs.

4. Now a word about OBAs. They can be either the worst thing ever added to papers or one of the best depending on who you ask
and what their priorities are. All natural paper has less reflectivity in the blue end of the spectrum (check Ernst's graphs for natural papers) which causes them to have a yellowish cast. The OBAs take invisible UV light and turn it into visible blue light which, if added in just the right amount (often in the paper itself instead of the emulsion), can neutralize the yellow cast and make the paper's reflectivity flat across the entire visible spectrum.  This neutralization does not require a lot of OBAs and so when you see a paper description say "low amount of OBAs" this is normally what they mean. Theoretically this neutralization can help produce more accurate colors.

The purpose of adding any more beyond this small amount is specifically to boost the brightness of the paper to make it puncher looking, which many consider a form of lying to the customer as this effect can fade in a relatively short time (which is why many hate OBAs). Also OBAs will fade faster when added to the emulsion than the paper, as their speed of fading is directly related to their exposure to UV light. So a print made from a paper with OBAs framed behind glass, which blocks a lot of UV, may take decades to fully fade. And even if it does fade it will only add a slight yellow cast to the photo as the paper returns to its normal color. But as most inkjet yellow inks fade faster than the other colors, the OBA fading causing the paper to become more yellow, may actually be able to partially make up for the loss of the yellow ink (you never know).

5. The final thing to consider is the printer itself with its ink, specific head design and algorithm which tells the head exactly how to lay down that ink. Each company has its own proprietary ink formulations which can interact differently with the different paper emulsions, and there's no other way to know what the result will be except to just test them all and see what you get, which is what Henry Wilhelm and Mark McCormick are doing (as money permits).   

Now I don't know if I've made your question easier or harder to answer, but as least maybe you now have a better understanding as to why there is no one simple answer.

 
Title: Re: Choosing the right paper
Post by: MHMG on April 03, 2018, 09:17:12 am

...  So a print made from a paper with OBAs framed behind glass, which blocks a lot of UV, may take decades to fully fade. And even if it does fade it will only add a slight yellow cast to the photo as the paper returns to its normal color. But as most inkjet yellow inks fade faster than the other colors, the OBA fading causing the paper to become more yellow, may actually be able to partially make up for the loss of the yellow ink (you never know).


OBAs have peak absorption between 360-370nm. Hence this band of energy excites the OBAs to fluoresce and  emit light in the blue range of visible light. This UVB 360-370 wavelength range is transmitted pretty well by both regular soda lime glass and acrylic glazings. So, OBAs will indeed fade under those glazings, but UV blocking glazings like museum glass and OP3 acrylic shut down the fluorescence completely thus immediately rendering the OBAs useless from a functional perspective.

And yes, the apparent visual increase in yellow caused by OBA fading does help to offset the loss of yellow due to yellow pigment or dye fading. This offset of yellowish hues shows up as a positive effect in nearly all the WIR tests of media containing OBAs because many modern inkjet systems fail the WIR test due to the pure yellow density patches, but this apparent benefit is actually a limitation of the current WIR test method. Any augmenting  of yellow hues in a typical image is also going to be a detriment to other colors like pale grays, light cyan/blue skies, etc. No free lunch. The Aardenburg 30 patch test target factors both yellow-blue and green-magenta hue and chroma shifts into the I* color scores, and typically, any OBA loss of fluorescence causes the overall color accuracy score to go down which is indeed the correct overall summation of visual changes observed by the viewer when OBAs quit fluorescing.

Lastly, I have been working hard over the last three years to add a dark storage discoloration component to the current Aardenburg light fade test protocol. I'm not quite there yet, but I'm getting very close to publishing this work. All "accelerated" light fade tests published to date by WIR, Aardenburg, and other labs have overlooked the problem of OBAs not remaining colorless after they degrade. This significant discoloration problem appears only later on as the print is retired to much lower light levels or dark storage because the discolored reaction bi-products are metastable and can be bleached back to colorless compounds (or nearly so) under high light intensity (hence not showing up in routine accelerated light fade tests). But the bleaching effect is of academic interest only because the staining returns again in just a few months of dark storage. Hence, we need to identify those media that have the problem and those that do not. A key to identifying those media is if they contain both TiO2 and OBAs in the same layer(s). That means pretty much all RC media and some "traditional fiber" and so-called "Baryta" papers (they may have some baryta in them but also lots of TiO2 or other whitening agents) suffer from this post-exposure dark storage discoloration, and its not pretty.

To give you some sense of how big the problem can be, I've measured b* yellowing changes as high as 25 in some RC media after they've been retired to dark storage. As another example, I have a test currently in progress with Epson's UCHD ink set (printed on a P600) using Epson Ultra Premium luster photo paper which is still passing the light fade part of my testing at 100Mlux hours even with a little loss of OBA fluorescence factored into that result. However, 20 and 50 megalux hours samples were pulled and placed in dark storage some time ago (then remeasured at 6months and soon to be 1year dark storage). When these remeasured results get factored into the final Aardenburg Conservation display ratings, the overall score is going to drop to about 20-30 Mlux hours. That's harsh, but it's another reality of media containing OBAs. As I mentioned earlier, all RC media have this OBA/TiO2 staining issue to varying degrees, so it's fair to say that the limiting factor for "archival fine art" ratings of modern pigmented inkjet inks printed on RC media is almost always going to become the media yellowing issues not the ink fading itself.

kind regards,
Mark
http://www.aardenburg-imaging.com

Title: Re: Choosing the right paper
Post by: mearussi on April 03, 2018, 09:56:36 am
Mark, thank you for the further clarification. We all learn from you.
Two questions:
1. I thought only "cheap" OBAs produced a color cast when they faded.
2. I did not know TiO2 was still used in Baryta paper. I thought one of the reasons for using Baryta was so you didn't have to use TiO2. TiO2 can really accelerate fading and even damage the paper base if its sealed in a frame due to its creation of ozone when hit by UV, which is why I assumed a paper whitened by Baryta was better than one whitened by TiO2. Maybe I'm wrong.
Title: Re: Choosing the right paper
Post by: Mark D Segal on April 03, 2018, 10:53:22 am
That means pretty much all RC media and some "traditional fiber" and so-called "Baryta" papers (they may have some baryta in them but also lots of TiO2 or other whitening agents) suffer from this post-exposure dark storage discoloration, and its not pretty.


This statement struck me as well, as I too was under the impression that generally Baryta is being used either instead of fluorescing agents or with a comparatively small component thereof (comparing say with Epson Premium Luster or Exhibition Fiber). An immediate example that comes to mind is the comparison of Ilford Gold Fibre Silk with Ilford Gold Fibre Gloss. Both are Baryta-containing papers, the former with a low OBA presence and the latter with none, to judge from my readings of paper white with an i1Pro2. Epson Legacy Baryta has a  low OBA presence while Legacy Platinum has none. So the questions are whether the specific non-Baryta whitening agents in these papers that have them are TiO2 or something else, whether they are in the substrate or in the coating, and whether we have test results for these papers giving comparative indication of OBA fading behaviour and its effects.
Title: Re: Choosing the right paper
Post by: MHMG on April 03, 2018, 11:08:54 am
Mark, thank you for the further clarification. We all learn from you.
Two questions:
1. I thought only "cheap" OBAs produced a color cast when they faded.
2. I did not know TiO2 was still used in Baryta paper. I thought one of the reasons for using Baryta was so you didn't have to use TiO2. TiO2 can really accelerate fading and even damage the paper base if its sealed in a frame due to its creation of ozone when hit by UV, which is why I assumed a paper whitened by Baryta was better than one whitened by TiO2. Maybe I'm wrong.

There may well be different quality grades of OBAs with respect to lightfastness, but pretty much everything I've tested in photographic and inkjet media fades, and when in media where TiO2 is present, develops additional staining as I mentioned in my earlier post.  For OBAs used in modern photo media, the rate of fading apparently has more to do with concentration and location in the media, not necessary due to "higher or lower grade" when the manufacturer chooses to incorporate OBA.

As for Baryta papers, it's important to note that true "full baryta" inkjet media do exist, but there are some glossy/luster "traditional fiber" media where the manufacturer gets away with calling it a baryta paper simply because a little Baryta is added into the whitening layer(s) in order to make the baryta claim. A bit disingenuous, IMHO, but if one likes the look and feel of the paper and it prints well, then I suppose it doesn't matter, unless of course the media yellows significantly over time.

cheers,
Mark
http://www.aardenburg-imaging.com
Title: Re: Choosing the right paper
Post by: Mark D Segal on April 03, 2018, 11:37:37 am

As for Baryta papers, it's important to note that true "full baryta" inkjet media do exist, but there are some glossy/luster "traditional fiber" media where the manufacturer gets away with calling it a baryta paper simply because a little Baryta is added into the whitening layer(s) in order to make the baryta claim. A bit disingenuous, IMHO, but if one likes the look and feel of the paper and it prints well, then I suppose it doesn't matter, unless of course the media yellows significantly over time.

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

Well, this begs the question, so let me ask you specifically - do you know whether Ilford Gold Fibre Silk and Epson Legacy Baryta contain TiO2, and if so, have you been able to test them for determining whether degradation creates uneven yellowing over a given number of equivalent years of say dark storage?
Title: Re: Choosing the right paper
Post by: mearussi on April 03, 2018, 12:46:24 pm
Yes, it would be really nice to know which papers contain TiO2.

I first became aware of the problem it caused when Ctein first discovered that the ozone TiO2 created was destroying so many of his fine art framed B&W prints (mentioned in his book "Post Exposure"). Due to the lack of air circulation in framed prints the ozone builds up oxidizing both the RC paper (causing it to crack) and silver (turning it black) in only a few months. Now I don't use RC paper nor is there any silver in my prints, but still ozone can't be good for either the inkjet paper or ink. So I would like to avoid the same fate happening to any of my photos that are also framed. 
Title: Re: Choosing the right paper
Post by: MHMG on April 03, 2018, 12:58:19 pm
Well, this begs the question, so let me ask you specifically - do you know whether Ilford Gold Fibre Silk and Epson Legacy Baryta contain TiO2, and if so, have you been able to test them for determining whether degradation creates uneven yellowing over a given number of equivalent years of say dark storage?

I evaluated the original IGFS and the newer Canson Baryta Photographic amongst other papers a couple of years ago when better funding enabled access to a portable XRF (X-ray Fluoresence) unit at a local conservation lab. I had picked these two media among others for XRF analyses because they are media "look-alikes" (as is Epson's Legacy Baryta), because both papers contain low amounts of OBA, and because they were some of the first non RC media in the Aardenburg database to exhibit this light-induced low intensity exposure problem (.e.g, the post exposure yellowing I have encountered on virtually all RC media). XRF detected TiO2 in both media, and the finding supports my hypothesis that it's the combination of OBA and TiO2 which leads to this post exposure yellowing/discoloration issue.

I'm also trying to research what light intensity level on display suppresses the yellowing by light bleaching. I haven't got a firm number yet, and it may ultimately be somewhat media dependent, but it appears that lux levels below 500 lux on display are low enough that the rate of staining proceeds faster than the rate of light bleaching. So, dark storage is simply the boundary condition for not enough light to suppress the extra yellowing (above and beyond the loss of OBA fluorescence) caused by OBA-TiO2 interactions for prints on long term display.

For more info, check out the notes, whitepoint stability measurements, and the I* curves in the PDF report for ID #223 in the Aardenburg Database. HP Z3200 inks on Canson Baryta Photographique. There are several other samples in the database that documented this problem during testing for those instances where I didn't get to measure the samples soon enough after removing them from the light fade units, and thus the staining and subsequent bleaching effects can be observed in the data. As I mentioned earlier, I'm trying to implement a more formal testing protocol that will routinely check for this problem and correctly factor it into the final test scores. Screening studies to check media whitepoint stability before conducting a full test is also a good approach.


kind regards,
Mark
http://www.aardenburg-imaging.com
Title: Re: Choosing the right paper
Post by: Mark D Segal on April 03, 2018, 01:01:38 pm
Thanks Mark, that's helpful. Good to know. I hope you can keep up the good work!
Title: Re: Choosing the right paper
Post by: Alan Goldhammer on April 03, 2018, 02:09:28 pm
Mark, thank you for the further clarification. We all learn from you.
Two questions:
1. I thought only "cheap" OBAs produced a color cast when they faded.
Epson Exhibition Fiber has lots of high quality OBAs and they create a color cast when they fade

Quote
2. I did not know TiO2 was still used in Baryta paper. I thought one of the reasons for using Baryta was so you didn't have to use TiO2. TiO2 can really accelerate fading and even damage the paper base if its sealed in a frame due to its creation of ozone when hit by UV, which is why I assumed a paper whitened by Baryta was better than one whitened by TiO2. Maybe I'm wrong.
Ozone production takes place at the surface of TiO2 only in the presence of nitrogen oxides.  It's not clear to me from a chemical perspective whether this reaction can take place on coated paper as the nitrogen oxides would have to penetrate the coating.  When I studied this issue several years ago it looked like Barium Sulfate was cheaper than TiO2 and that might have been the principal reason for using it as a paper whitener (there may have been other reasons as well).
Title: Re: Choosing the right paper
Post by: mearussi on April 03, 2018, 03:30:35 pm
Epson Exhibition Fiber has lots of high quality OBAs and they create a color cast when they fade
Ozone production takes place at the surface of TiO2 only in the presence of nitrogen oxides.  It's not clear to me from a chemical perspective whether this reaction can take place on coated paper as the nitrogen oxides would have to penetrate the coating.  When I studied this issue several years ago it looked like Barium Sulfate was cheaper than TiO2 and that might have been the principal reason for using it as a paper whitener (there may have been other reasons as well).
So you're saying that the color cast isn't just from the return of the paper back to the normal yellow cast it had before OBAs were added? So what color(s) do the OBAs create when they decay?
Title: Re: Choosing the right paper
Post by: MHMG on April 03, 2018, 04:51:36 pm
So you're saying that the color cast isn't just from the return of the paper back to the normal yellow cast it had before OBAs were added? So what color(s) do the OBAs create when they decay?

Check out the PDF report for ID #210 in the Aardenburg light fade database. It tells what discerning printmakers need to know about Epson Exhibition Fiber paper.  The report notes plus the media whitepoint stability graph on page 5 plus the visual appearance of the target images accurately reproduced in the report which show higher and higher exposure doses turning the media more and more yellow all document the sad story of this paper not living up to its "bright white" expectations over time. Some of the yellowing is caused by loss of OBA fluorescence, but the yellowing goes beyond what can be explained solely by loss of OBA fluorescence, and this strong yellowing IS NOT caused by the OBA-TiO2 dark storage staining issue either (Epson EFP is loaded with OBA but not any TiO2, again confirmed with XRF analysis).

regards,
Mark
http://www.aardenburg-imaging.com
Title: Re: Choosing the right paper
Post by: enduser on April 03, 2018, 09:08:00 pm
From the discussion so far I'm beginning to see where caution applies in choosing paper.  As someone on this thread said, it's complicated. I almost feel like asking Mark MHMG what papers he uses for his own work, thereby simplifying the selection process.
Title: Re: Choosing the right paper
Post by: mearussi on April 03, 2018, 10:03:51 pm
Remember that longevity is only one aspect of choosing a paper. It also has to look good with your image.

First find a paper that maximizes your image then focus on how you can make it last as long as possible. For instance, I have recently switched from Canson's Platine (no OBAs) to Canson's new Baryta Prestige, even though it has a small amount of OBAs added, because of its superior color reproduction and clarity for my printer/ink combination compared to Platine. But I also know how to protect it and slow down its fading by applying Print Shield, a spray overcoat, which, according to Mark's tests, will add approximately 25% of display life to it. I could even extend that further if I decided to use a UV glass when framing.