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Author Topic: How do you tell if a paper is acid-free or has OBA's?  (Read 12386 times)
Mark F
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« on: November 18, 2009, 09:08:56 PM »
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As a new printer I've followed the various discussions about acid-free papers, and papers without OBA's.  But how are people finding this info out?  I've gone to the Epson, Ilford and Hahnemuhle sites and none of them state whether their papers have, or do not have OBA's. I've even emailed Epson tech support and been told that that information is not disclosed. So how can I find out about a paper? Is there a site that lists this info?  Is it fair to assume that if a paper is not specifically described as acid-free that it is not?

Thanks for your help.
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Wayne Fox
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« Reply #1 on: November 18, 2009, 11:52:47 PM »
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Quote from: Mark F
As a new printer I've followed the various discussions about acid-free papers, and papers without OBA's.  But how are people finding this info out?  I've gone to the Epson, Ilford and Hahnemuhle sites and none of them state whether their papers have, or do not have OBA's. I've even emailed Epson tech support and been told that that information is not disclosed. So how can I find out about a paper? Is there a site that lists this info?  Is it fair to assume that if a paper is not specifically described as acid-free that it is not?

Thanks for your help.

I suppose you could buy a cheap blacklight from the hardware store.  The more OBA's the brighter the paper will glow in the dark.

Seems most companies that don't tell you whether the paper has OBA's or not, it's because it does.  Most of the ones that don't are pretty explicit about not having them.  I'm sure there might be exceptions.
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Jonathan Wienke
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« Reply #2 on: November 19, 2009, 08:45:40 AM »
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+1 on the blacklight selection. You can also use violet LED lights (470nm) to detect OBAs. Not too long ago McDonalds had a LED toy in their Happy Meals (some secret agent invisible ink pen thing) that had a nice 470nm violet LED in it that makes things fluoresce nicely. There's also UV/violet LED flashlights, etc...A Google search will get you hundreds of hits.

As to acid-free, I don't know of any easy test; you'd have to do a chemical analysis of the paper.
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Mark F
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« Reply #3 on: November 19, 2009, 09:00:06 PM »
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Thank you Wayne and Jonathan - the black light is certainly a fairly simple way to go. But what puzzles me is that in reading the threads in the other forums on LL it seems that many people already know that certain papers do, or do not contain OBA's or acid.  Is there a central source where someone(s) have already compiled this information?
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Mark
Wayne Fox
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« Reply #4 on: November 19, 2009, 09:10:33 PM »
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Quote from: Mark F
Thank you Wayne and Jonathan - the black light is certainly a fairly simple way to go. But what puzzles me is that in reading the threads in the other forums on LL it seems that many people already know that certain papers do, or do not contain OBA's or acid.  Is there a central source where someone(s) have already compiled this information?

I don't recall one.  I suppose spending time with Google might find something.  As I said if you want to make sure they don't have OBA's, then stick to the ones that tell you.  Some companies such as Moab actually provide the same paper both ways, usually calling the non OBA papers natural and the OBA papers bright.  They make some very nice papers.

personally I don't pay much attention to the OBA thing.  I'm guess I'm skeptical that 50 years from now anything I do will still be hanging on anyones wall, and even with OBA's I think high quality papers will still look pretty good unless they haven't been displayed properly.  Who knows ... 50 years from now inkjet printing might seem as ancient as daguerreotype is now.

I guess if I was famous and collected I might feel differently ... for now I just want my stuff to look good and know the paper is from a high quality maker.

I know you didn't ask that question ... guess I'm just trying to rationalize my own point of view. Those that feel differently I completely respect their point of view as well.
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NikoJorj
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« Reply #5 on: November 20, 2009, 10:33:23 AM »
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Quote from: Mark F
it seems that many people already know that certain papers do, or do not contain OBA's or acid.  Is there a central source where someone(s) have already compiled this information?
For OBAs : http://www.pusztaiphoto.com/articles/print...s/webchart.aspx
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Nicolas from Grenoble
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JeffKohn
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« Reply #6 on: November 20, 2009, 11:53:42 AM »
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I think most paper manufacturers do state if their paper is acid free. If they don't mention it I would be suspect.

Just for example:

http://www.museofineart.com/museomax.aspx
http://moabpaper.com/colorado-fiber-gloss-245
http://www.hahnemuehle.com/prod/us/461/592...ta-315-gsm.html (click link for PDF datasheet)

These manufacturers all have pretty detailed specs, although there are some variations in how they report them. Moab doesn't bother stating acid-free for their cotton-rag papers (I guess they figure it's a give), only the alpha-cellulose papers. They all explicitly mention OBA-free on the papers for which that is the case, which can be understood to imply that they do use OBA's in papers for which they don't state otherwise.
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joedecker
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« Reply #7 on: November 20, 2009, 08:16:16 PM »
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As far as acid-free goes, I recently spotted this little pH testing pen ( http://www.redimat.com/products/accessorie...esting-pen.html ) which looks like it might be helpful, but I haven't tried it.  At under $5, it might be worth a shot!

(I've only professionally worked with a few papers whose properties are pretty well known, so I haven't faced the problem myself.)

--Joe
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Joe Decker
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Mark F
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« Reply #8 on: November 21, 2009, 08:01:28 PM »
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Wayne, you are right of course. I doubt if anyone other than my immediate family would possibly care about my photos, and even that is far from certain. But I would like them to last at least for the lives of grandchildren. What worries me are the reports I've read about OBA enhanced papers beginning to fade in 5 - 10 years.  I'm vain enough to want my prints to last longer than that. On the other hand, as long as the file exists it should be possible to make another print...

Quote from: Wayne Fox
personally I don't pay much attention to the OBA thing.  I'm guess I'm skeptical that 50 years from now anything I do will still be hanging on anyones wall, and even with OBA's I think high quality papers will still look pretty good unless they haven't been displayed properly.  Who knows ... 50 years from now inkjet printing might seem as ancient as daguerreotype is now.

I guess if I was famous and collected I might feel differently ... for now I just want my stuff to look good and know the paper is from a high quality maker.
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Mark F
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« Reply #9 on: November 21, 2009, 08:14:31 PM »
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Thanks Joe, I'll look in my local art supply store for that pen

Nicolas, could you help me understand the graphs? For example, I compared the Epson Cold Press Bright against the Cold Press Natural papers, also leaving the X-Rite calibration in place.  Presumably the Bright paper is the one with OBA's?  Yet at wavelengths less than 420mm the Bright reflectance is lower than Natural, and between approximately 420 and 470mm the Bright has higher reflectance. At  470mm and higher, all three are about the same.  So what am I looking at and where does the OBA effect show up on the graph?

Thanks again to everyone.
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NikoJorj
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« Reply #10 on: November 22, 2009, 04:04:48 AM »
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So what am I looking at and where does the OBA effect show up on the graph?
OBAs are fluorescent dyes, ie they reflect a given wavelength (here near UVs around 350-400nm) into another wavelength (here blue-violet around 420-500nm).
Btw, this is why most of the OBA-charged appear rather cool : they reflect more blue light than normal.

These graphs are spectral responses: they plot the magnitude of the reflected response vs. its wavelength.
Incoming light is supposed to be regularly distributed, or may be distributed as the Xrite tile (not quite sure).

So, OBAs show both a characteristic gap at near-UV wavelength (this kind of light is absorbed by OBAs) and corresponding bump at 420-500nm (this is how the OBAs reflect the absorbed UVs, so there may be more of these wavelengths than in the incoming light, hence the values higher than 1.0 on the graph).

Compare Entrada Natural to Entrada Bright White, they're archetypal of a paper without (any?) OBAs (gentle curve just like the Xrite tile) vs. one with lots of it (curves starts near 0 then overshoots past 1 in the beginning of the graph).
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Nicolas from Grenoble
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Mark F
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« Reply #11 on: November 22, 2009, 04:46:09 PM »
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Thanks very much, Nicolas. I see what you are saying.

By the way, now that I have my first printer I cannot say how much fun I am having. I do not think I have had so much (photographic) fun since I saw my first print come up in the developer tray so many years ago.

Mark



Quote from: NikoJorj
So, OBAs show both a characteristic gap at near-UV wavelength (this kind of light is absorbed by OBAs) and corresponding bump at 420-500nm (this is how the OBAs reflect the absorbed UVs, so there may be more of these wavelengths than in the incoming light, hence the values higher than 1.0 on the graph).

Compare Entrada Natural to Entrada Bright White, they're archetypal of a paper without (any?) OBAs (gentle curve just like the Xrite tile) vs. one with lots of it (curves starts near 0 then overshoots past 1 in the beginning of the graph).
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Mark
Wayne Fox
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« Reply #12 on: November 22, 2009, 06:22:54 PM »
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Quote from: Mark F
Wayne, you are right of course. I doubt if anyone other than my immediate family would possibly care about my photos, and even that is far from certain. But I would like them to last at least for the lives of grandchildren. What worries me are the reports I've read about OBA enhanced papers beginning to fade in 5 - 10 years.  I'm vain enough to want my prints to last longer than that. On the other hand, as long as the file exists it should be possible to make another print...


If an image printed on high quality paper from a reputable manufacturer appreciably degrades in 5 to 10 years, I'm doubting OBA's were the primary cause, if they even contributed at all.  I'm not sure what reports you've read, but as with anything on the net it's hard to know what to believe. There is also plenty of information that indicates OBA's simply brighten the media until they wear out at which point they have no affect so the paper color is the same as non OBA papers would be after the same amount of time.  One such article

http://lexjetblog.files.wordpress.com/2009...sbjuly43-45.pdf

I'm certainly not an expert, but from what I can read those that claim OBA's can seriously affect print longevity seem to base this on a lot of theories, but provide no real evidence.
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JeffKohn
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« Reply #13 on: November 23, 2009, 02:11:20 PM »
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My understanding is that OBA's primarly affect paper white, and to some extent the color balance of lighter colors. That nice bright paper base (which is whole point of OBA's) will fade as the OBA's deteriorate, and eventually the paper will yellow (in fact it will probably more more yellow than a good OBA-free paper once the OBA's fade). So the overall appearance of your image will change with a noticeable shift towards a warmer color base, but I don't think it will have any impact on fading the ink. (It _will_ affect the apparent contrast of the print though).

Epson had a matte paper a while back (Enhanced Matte maybe?) that was chock full of OBA's, and which faded more quickly than is typical. From what I recall the prints would show noticeable yellowing in under a year.
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Wayne Fox
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« Reply #14 on: November 23, 2009, 02:38:29 PM »
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and eventually the paper will yellow (in fact it will probably more more yellow than a good OBA-free paper once the OBA's fade).

The paper will appear more yellow because that is it's natural color. As far as yellowing more than an OBA version of the same paper, I've seen a lot of speculation on this but I'm not sure there is any strong evidence this is the case ... at least as a general statement that applies to all papers.

However,  an image color balanced for printing on a paper containing OBA's may indeed appear much warmer over time than if you print on a non OBA paper, where you can somewhat compensate for the yellow paper.  In this case as the OBA's fade the paper may appear to have yellowed more than the same print on a non OBA paper.  Since you don't use the same paper profile for the two papers, and the profile itself is compensating for both the OBA's as well as the papers natural color, two resulting prints on two identical papers, one with OBA's and one without will most likely appear quite different 50-100 years from now, because the profile compensated for the "cool" OBA paper and printed it a little warmer, as well as the warm natural paper and printed it a little cooler.

I guess the real question is how fast do the OBA papers "yellow" ... how long does it take for them to loose their whitening ability.  If indeed it is a matter of only 5 or 10 years then some concern is in order.  This doesn't appear to be the case, most feel it is more in the order of > 50 years.

As far as permanence, I'm pretty sure that most RC papers contain OBA's, which are the papers used for most longevity tests.  currently Epson Premium Luster from a 7900 displayed under UV glass is rated at >200 years.

That leads me to another thought ... if the OBA's convert the invisible UV spectrum of light into a visible spectrum, wouldn't displaying the print under UV absorbing glass negate this effect almost entirely, so using an OBA paper has no advantage?  I researched this briefly a couple of times and didn't find an answser.


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NikoJorj
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« Reply #15 on: November 23, 2009, 02:58:22 PM »
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Quote from: Wayne Fox
I'm certainly not an expert, but from what I can read those that claim OBA's can seriously affect print longevity seem to base this on a lot of theories, but provide no real evidence.
From what I understood from the topic (Mark aka MHMG has posted here some findings and facts, among others, see eg here), the worst problem could be some differential OBA fading (ie yellowing around the edges of the paper, something rather common to see in old paper archives), and might be more related to papers with OBA in the surface (as opposed to in the paper core).

I'd certainly agree that the subject is confusing, to conclude on a broader consensus.  
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Nicolas from Grenoble
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Mark F
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« Reply #16 on: November 23, 2009, 05:41:37 PM »
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So I guess the jury is still out on this and only time will tell.  But I've made up my mind on how I'll proceed.  For something that is good enough to sell or hang on the wall I will go acid-free, no OBA. The cost will be a small part of the effort.
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Mark
Wayne Fox
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« Reply #17 on: November 23, 2009, 08:32:17 PM »
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Quote from: Mark F
So I guess the jury is still out on this and only time will tell.  But I've made up my mind on how I'll proceed.  For something that is good enough to sell or hang on the wall I will go acid-free, no OBA. The cost will be a small part of the effort.
Certainly as far as you are concerned that's great. Because who knows how many will read this thread in the future (considering messages on these forums almost always show up in the top few hits when googling anything photographic), I offer the following comment ... please don't take it as criticism regarding your personal decision or me trying to change your mind.

But as far as "the jury is still out" statement,  this is true of anything to do with inkjet printing in general, and in fact is more applicable to inkjet printing and the inks themselves than it is to the OBA questions raised in this thread.  OBA's have been used in papers for a lot longer than the ink's we currently use, and while there is still some "controversy" regarding their affect, we probably know more about them than about the rest of the current inkjet process ... after all it is still a very new technology and all we have to go on are accelerated aging test.

Certainly if trying to produce museum quality maximum archival prints then acid free non OBA papers may be in order.  But there is plenty of evidence that OBA containing papers, as well as other paper making techniques are more than adequate for extreme print longevity ... certainly decades longer than any color process we had as little as 10-15 years ago when the only real option was silver halide technology.

I offer one comparison example. According to Wilhelm permanence ratings images printed with an Epson 7900 on Epson Exhibition Fiber, which is not a 100% acid free rag based paper (it is wood pulp based) and contains OBA's is rated at 90 years when displayed under glass, 150 years when displayed under UV filtered glass, 44 years when not protected at all and greater than 200 years  in album dark storage, and this last test includes paper yellowing.  Compared to Somerset Velvet which is a 100% acid free cotton rag paper with no OBAs (and is a gorgeous paper) - 62 years framed under glass, 128 years under UV glass, 37 years when unprotected, and >200 years dark album storage (which again includes paper yellowing).

Personally I believe prints produced on todays top end inkjet printers on high quality media will in all likelihood come to the end of their useful life from some physical destruction(fire, water, lost, trashed), not from fading or yellowing.  Those that do fade or yellow to the extreme, it will most likely result from improper care, and not from the properties of the ink and paper used to produce the print.
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JeffKohn
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« Reply #18 on: November 23, 2009, 11:19:41 PM »
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Quote
The paper will appear more yellow because that is it's natural color. As far as yellowing more than an OBA version of the same paper, I've seen a lot of speculation on this but I'm not sure there is any strong evidence this is the case ... at least as a general statement that applies to all papers.
I didn't mean to say the OBA's themselves will cause more yellowing than if the same paper had no OBA's added. I'm just thinking that with some of the better OBA-free papers that aren't specifically intended to be "warm", the manufacturer works pretty hard at getting the paper base as white as possible, so that the paper base in these papers is probably whiter than what manufacturers are starting with when they add OBA's.
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Alan Goldhammer
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« Reply #19 on: November 24, 2009, 01:47:07 PM »
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Quote from: NikoJorj
OBAs are fluorescent dyes, ie they reflect a given wavelength (here near UVs around 350-400nm) into another wavelength (here blue-violet around 420-500nm).
Btw, this is why most of the OBA-charged appear rather cool : they reflect more blue light than normal.
I knew my PhD in chemistry would come in handy one day.  What is mentioned above is not correct.  The molecule absorbs light of a lower wavelength and emits light of a higher wavelength.  For example a fluorescent light bulb uses trace amounts of mercury to emit UV light which causes a phosphor to absorb it and then emit visible light.

Alan
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