Author Topic: Optical brightening agents (OBA)  (Read 994 times)

Ian Watson

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Optical brightening agents (OBA)
« on: April 18, 2023, 01:21:00 »
May I please pick your brains? I am taking a deeper look at inkjet photo papers, not least with a view towards longevity.

Optical brightening agents, also known as optical brighteners or OBAs, make a paper appear more white by absorbing ultraviolet light and re-emitting it, usually towards the blue end of the spectrum. These gradually degrade with exposure.

Some sources hold that the ideal is no OBAs in a photo paper. Yet a number of eminent manufacturers claim exceptional longevity even for papers with what seems to be termed "low amounts" of OBAs. So it is probably a bit complicated.

My point of reference is a number of prints from the early 1960s that my father-in-law has. They were made by a professional and still look very, very good. It would be nice to think that my children might treasure a few of mine a few decades from now.

All advice and information will be gratefully received!

Frank Fremerey

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Re: Optical brightening agents (OBA)
« Reply #1 on: April 18, 2023, 09:18:34 »
Inkjet technology in the longevity and quality sense of the current "large pigment ink" following Epsons breaktrough developments many years ago, has not existed in the 1960ies. So you will probably dealing with C-prints or Baryta-prints on photo paper made by Ilford, Kodak or Fuji and the like.

The worst of these can keep original colors for 40 years, the best for 80 years. A moment please, I will find you a reference point:
You are out there. You and your camera. You can shoot or not shoot as you please. Discover the world, Your world. Show it to us. Or we might never see it.

Me: https://youpic.com/photographer/frankfremerey/

Frank Fremerey

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Re: Optical brightening agents (OBA)
« Reply #2 on: April 18, 2023, 09:20:44 »
this would be my reference point: http://www.wilhelm-research.com/
You are out there. You and your camera. You can shoot or not shoot as you please. Discover the world, Your world. Show it to us. Or we might never see it.

Me: https://youpic.com/photographer/frankfremerey/

Erik Lund

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Re: Optical brightening agents (OBA)
« Reply #3 on: April 18, 2023, 10:58:16 »
Long time ago I looked into inks and paper and also came up with Epson.
Please remember; Everything is impermanent...
Erik Lund

Ian Watson

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Re: Optical brightening agents (OBA)
« Reply #4 on: April 18, 2023, 15:15:30 »
So you will probably dealing with C-prints or Baryta-prints on photo paper made by Ilford, Kodak or Fuji and the like.

The worst of these can keep original colors for 40 years, the best for 80 years.

Thank you, Frank.

The prints from the '60s are fibre-based darkroom prints. Properly made, they can last. It looks like modern inkjet prints with pigment inks (which I have) will do nicely.

Ironically, I love Ilford's Gold Fibre Silk but that isn't made any more. It has a small amount of OBAs. I never worried about it until I started reading.

Ian Watson

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Re: Optical brightening agents (OBA)
« Reply #5 on: April 18, 2023, 15:17:28 »
Please remember; Everything is impermanent...

Wise words.

Dogman

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Re: Optical brightening agents (OBA)
« Reply #6 on: April 18, 2023, 15:51:19 »
I'm not printing right now since my second expensive Epson photo printer stopped transporting paper (same thing happened to the first) and I'm reluctant to buy another.  However, I did print for several years and I researched a lot before settling on papers, inks, etc.

According to what I read from Wilhelm (THE source of longevity testing at the time), prints made on high rag content matte papers (called "art" or "fine art" papers by manufacturers) with pigment inks had a projected lifespan even longer than archival processed and printed black and white photographs using chemicals in a wet darkroom.  There were several further stipulations concerning storage, display, etc., but the basics were always the same.  So that's what I used--cotton rag papers and pigment inks.  Oddly enough, the use of pigments on rag papers is an old process used by artists centuries past and it was still holding up today.

As far as OBAs are concerned, they were not considered archival so I didn't buy papers that contained them.  However, some sources said the only factor to consider when using those types of papers was that the bright whites of the paper would probably fade over time leaving all other attributes intact.  In other words, the print might look less bright but would still be archival.  I haven't kept up with the discussion recently so I don't know if new research has been conducted.

 
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Ian Watson

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Re: Optical brightening agents (OBA)
« Reply #7 on: April 18, 2023, 17:34:49 »
Thank you. I will take a look at the rag papers. Since I am looking for new papers anyway, I may as well avoid OBAs.

That's rotten luck with your Epsons! My Canon probably has not seen as much use as you gave them but it is still trucking along nicely.

Dogman

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Re: Optical brightening agents (OBA)
« Reply #8 on: April 19, 2023, 15:22:42 »
I'm considering a Canon for a future purchase. 
"If it's more than a hundred feet from the car, it's not photogenic."--Edward Weston

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