Gast
Hello,
According to the FOTOIMPEX catalogue, CA PW paper does not contain any fluorescent whitening agents. So why does the paper glow when you shine a UV lamp (‘black light’) on it? If you want to try it out for yourself: UV lamps are available in any electrical shop, and a bulb costs around 3
uworischki
I had a look at the link – interesting, but I hadn’t really given lighteners much thought before... What effect do they have?
Gast
" ... Fluorescent whitening agents were occasionally added to paper as early as the 1940s, but they only became widely used from around 1950 onwards. The disadvantage – apart from the unnatural whiteness – is that the paper yellows more quickly and more severely."
That’s what the link says. I can confirm the yellowing with Ilford Multigrade PE from the 1980s, but not with MGIV baryta paper. It probably depends on the quality of the optical brighteners.
MirkoBoeddecker
Hello Ferdinand,
We recently had a discussion on this topic with the manufacturer of our papers.
Please note that our catalogue does not mention any "embedded developers or fluorescent whitening agents".
This means that we do not use these additives during the production process of the photographic paper, i.e. when coating the base paper.
What we cannot influence is the production of the base paper itself.
The market has shrunk so much in recent years that more or less everyone is in the same boat and has to use the same base paper.
In this context, some sad news first: the Museum weight base paper is no longer being produced and will therefore be phased out this year.
The good news: according to the paper manufacturer, the new premium weight base (slightly thinner than Museum, probably 240–280 g) is free from fluorescent whitening agents, as a higher degree of whiteness has been achieved through a new bleaching process.
This is the first I’ve heard of the ‘yellowing’ issue. Of course, when fluorescent whitening agents degrade, they lose their effect, making the paper appear yellower, but that shouldn’t result in accelerated ‘yellowing’.
The unresolved mystery remains: do the degradation products of the broken-down fluorescent whitening agents affect the longevity of the image or not?
The biggest problem with this issue concerns the Ilford papers from the 1980s mentioned earlier, as Ilford was a pioneer in this field and produced truly bright white, high-brilliance papers.
Technology has advanced since then.
With Classic, neither a deterioration of the fluorescent whitening agents nor any ageing issues have occurred to date.
Best regards,
Mirko
FOTOIMPEX
