Optical brightener

[Matt Rutkowski]

I developed few pice of color paper in RA4. The paper is 20 years old. White border is not so clean as it should be. I think I should use optical brightener - Tinopal SFP but it's hard to get. Can anyone recommend good replacement for Tinopal SPF?

 

[pentaxuser]

I think that optical brightener only makes the picture brighter(allegedly). The optical brightener I have used was said to improve brightness of the colours by 10% but I am not sure it made enough difference to be seen. If the white border is not so clean as in going a yellow colour this may be age-fogging and might require another solution.

pentaxuser

 

[Ian Grant]

No Mike, optical brighteners work. I have a bag of Tinopal, and a few bottles of Optical brightener solution - I've never wanted to use it

Ian

 

[Photo Engineer]

You could use Phourwite REU or something similar. I may have garbled that name. Sorry.

You run the risk of making blacks turn blue, and the brightener does not work under tungsten lights.

PE

 

[fdonadio]

You could use Phourwite REU or something similar. I may have garbled that name. Sorry.

Maybe you meant Blankophor REU?

 

[Photo Engineer]

There is both of these AFAIK.

They are all yellow powders that turn white when struck by UV irradiation. Gradually, they decompose and give an even yellower border than before unless the right one is selected for the paper.

PE

 

[fdonadio]

There's a thread here that talks about using Benzotriazole with color paper/developer to reduce base fog...

 

[Rudeofus]

Since you seem to live in EU, I recommend you contact Fototechnik Suvatlar. They have a raw compound called "WA Weißaufheller" near the end of their price list, which is essentially what you want. It's not exactly cheap, but it works in tiny amounts and the powder compound lasts forever.

 

[pentaxuser]

The OP problem seems to be his "off-white" borders. Apart from fdonadio's post which addresses the base fog question do any of the others which seem to be about optical brighteners address what appears to be an age-fogging problem.

I have some old Kodak RA4 paper. The colours don't look too bad but the borders are a creamy-yellow and not white. Will immersion in an optical brightener cure that?

Thanks

pentaxuser

 

[dE fENDER]

I have some old Kodak RA4 paper. The colours don't look too bad but the borders are a creamy-yellow and not white. Will immersion in an optical brightener cure that?

If it is color age fog, it is possible that optical brightener will not help too much, but some effect should be in any case. Try to use antifog first. It the old paper base has been yellow, effect of brightener will be more evident.

Try to blix stripe first without developing and see is it yellow or not.

 

[pentaxuser]

Since you seem to live in EU, I recommend you contact Fototechnik Suvatlar. They have a raw compound called "WA Weißaufheller" near the end of their price list, which is essentially what you want. It's not exactly cheap, but it works in tiny amounts and the powder compound lasts forever.

So WA Weissaufheller which appears to be a "white lightener" as a literal translation will turn or at least help turn the borders back to white? Does it only act on age-yellowing borders or does it also brighten the print as a whole. Is this the same stuff that doesn't work under tungsten lights as PE has commented? I presume that the chemical needs the UV component of daylight to work. If I am right in this presumption, once it has worked in UV, can I take it that the brightening effect is permanent i.e. it then doesn't lose its effect if the print is kept under tungsten light.

Is this the same stuff to which PE refers when he says that eventually the yellowing returns with a vengeance so that you may have jumped from the frying pan only to land in the fire so to speak unless the powder is the right one for the paper?

I appreciate that some of my points may need clarification from PE rather than yourself but I am just trying to get a clear idea of what this stuff can and cannot do.

Thanks

pentaxuser

 

[Photo Engineer]

Remember, the paper and the process both contain brighteners.

The effect is only seen in the presence of UV radiation.

PE

 

[pentaxuser]

Remember, the paper and the process both contain brighteners.

The effect is only seen in the presence of UV radiation.

PE

Just to clarify: I think you are saying that the effect is only there in UV light which for the most part will be daylight but once you view the print again in tungsten it will appear to be less bright. Presumably it it brightens/lightens towards the colour white those creamy/yellowish borders and then in tungsten light the creamy/yellowish colour appear again or does it?

Thanks

pentaxuser

 

[Photo Engineer]

That is correct.

PE

 

[pentaxuser]

Once you have decided what to do, I would certainly like to know what your experience was.

Thanks

pentaxuser

 

[Rudeofus]

So WA Weissaufheller which appears to be a "white lightener" as a literal translation will turn or at least help turn the borders back to white? Does it only act on age-yellowing borders or does it also brighten the print as a whole. Is this the same stuff that doesn't work under tungsten lights as PE has commented? I presume that the chemical needs the UV component of daylight to work. If I am right in this presumption, once it has worked in UV, can I take it that the brightening effect is permanent i.e. it then doesn't lose its effect if the print is kept under tungsten light.

Since PE already answered most of your question, here a quick summary of what optical brighteners actually do: they absorb UV photons and emit blue photons. As they age, they will turn yellow, which is likely what happened to Matt's now yellow paper stash. The emitted blue light makes the paper look brighter to our eyes, but obviously only in the presence of UV light.

PS: I am not entirely sure how optical brighteners react to different light sources: real tungsten light is the easiest one, it has almost no UV component and will not do much, but at least in Europe real tungsten light is on its way out. Fluorescent light initially starts as UV light which is then converted to visible light, not sure at which conversion ratio. It's also got its own light color plus a discontinuous spectrum, no idea what this yellow RA-4 paper will look like with this type of illumination. LED light is again different, starting with a powerful blue LED, with some of its light output converted to yellow/green, again with its own light color plus a discontinuous spectrum. Put altogether, today's artificial light sources may bring more issues to the table than optical brighteners can create or solve by themselves.

 

[pentaxuser]

When I used optical brightener it was in my early days of RA4 and it sounded like a good idea- if everything looked brighter what was there not to like. As I said in an earlier post I could never see much, if any improvement, and while I always looked at the print in the darkroom in tungsten light where I now know I would not have seen an improvement, I usually looked at them again in daylight.

The stuff never looked powerful enough to change a yellowish border to anywhere near white. I may be making a wrong assumption here but I get the impression that benzo which does a great job on B&W paper will have no effect on RA4 paper.

I just want to avoid giving the OP the impression that optical brighteners are a complete answer. He may buy stuff and find it a real disappointment.

pentaxuser

 

[Rudeofus]

Benzotriazole, and to a much higher degree Phenyl-Mercaptotetrazole (see Michael R.'s thread in B&W section) create a bluish image tone by changing the course of development for image silver. Since all image silver is removed in color processes, I would not expect any effect from BTAZ and PMT.

 

[pentaxuser]

Since PE already answered most of your question, here a quick summary of what optical brighteners actually do: they absorb UV photons and emit blue photons. As they age, they will turn yellow, which is likely what happened to Matt's now yellow paper stash. The emitted blue light makes the paper look brighter to our eyes, but obviously only in the presence of UV light..

Thanks. I think you are saying that it is the ageing process of optical brighteners that makes them turn yellow but unless this is optical brighteners already in the paper I cannot see how this applies to the OP's 20 year old paper on which he has printed but then discovered his borders are yellowish. If it is optical brightener built into the paper that has turned yellow due to the passing of time i.e. 20 years then will more optical brighteners reverse this yellowing albeit for a period only?

If it can reverse the damage then he achieves something albeit a temporary something but if the paper was simply old and has yellowed due to age then it seems that am I right that nothing will reverse the process?

He is considering spending money to cure his yellow borders. Given the age of the paper will this work?

If it were my money this is what would be crucial for me


pentaxuser

 

[Photo Engineer]

The answer is "give up". In this case you are chasing your tail. The paper is old. Fog and decomposing brighteners have made the paper yellow. Anything to fix this will be just a band aid.

PE

 

[newcan1]

Benzotriazole, and to a much higher degree Phenyl-Mercaptotetrazole (see Michael R.'s thread in B&W section) create a bluish image tone by changing the course of development for image silver. Since all image silver is removed in color processes, I would not expect any effect from BTAZ and PMT.

Not so. The use of benzotriazole will restrain the silver fog development, and with it, the dye couplers that give rise to the yellowish base. I have used BZT many times with older color papers, and the results are often very impressive. Much less BZT is needed with color paper than with black and white. The only paper I have found thus far that it has not worked with for some reason is Kodak Portra, although in that case the paper was very fogged.

 

[Andrew O'Neill]

Or you could just have some fun and make cameraless faux POP prints, like jnanian!

 

[Gerald C Koch]

The problem with optical brighteners like Tinopal is that they work only in the presence of UV light. No UV no brightening. Of course UV light is something you do not want to expose your prints to routinely since this would create an even bigger problem fading.

 

[Photo Engineer]

Not so. The use of benzotriazole will restrain the silver fog development, and with it, the dye couplers that give rise to the yellowish base. I have used BZT many times with older color papers, and the results are often very impressive. Much less BZT is needed with color paper than with black and white. The only paper I have found thus far that it has not worked with for some reason is Kodak Portra, although in that case the paper was very fogged.

I think that you have misunderstood the answer you are referring to. Antifoggants do change the fog in color prints and color film, but they don't change the tint on purpose. Often, they introduce color shifts by changing the way each layer develops. The most major example is with color paper becoming yellow by retarding the top (cyan) layer more than the others. Often PMT is the biggest offender because it is adsorbed most strongly in the top layer.

PE

 

[newcan1]

I think that you have misunderstood the answer you are referring to. Antifoggants do change the fog in color prints and color film, but they don't change the tint on purpose. Often, they introduce color shifts by changing the way each layer develops. The most major example is with color paper becoming yellow by retarding the top (cyan) layer more than the others. Often PMT is the biggest offender because it is adsorbed most strongly in the top layer.

PE

Perhaps so. I was reacting to the statement, "Since all image silver is removed in color processes, I would not expect any effect from BTAZ and PMT." Perhaps I misunderstood that. In my own experience benzotriazole has been invaluable in eliminating slight base fog (the kind that leads to a yellowish tint). I have not noticed any crossover, visually at least, and filtration has never been out of the realms of normality. I have never used PMT.