I've just waded through Ilford's and Agfa's web sites .... I have a head ache.Originally Posted by Thilo Schmid
I found "fading" information on Ilford's site, but not on Agfa's (other than, "Our paper is awful good when it comes to fading") - and I couldn't navigate to anything worthwhile on Fuji's. Could you help with a few specific addresses here?
I have a few questions - Ilford decribes their paper as "Ilfocolor E" ... and I'm not sure that is the same stuff that I have cached in my refrigerator. Agfa lists "Signum II", which, again, is not the same as what I had used.
Probably, there have been, over time, advances in "permanence" qualities.
I can only say that the Ilfocolor prints I have hanging appear to be "fresh". I really cannot duplicate processing - those in question were processed with Photocolor (early) and JOBO/ Russell, JOBO/Trebla - and JOBO (Tetenal) chemicals - and I have no doubt that the chemical process has a significant effect on color balance and longevity.
The "Fading" information I was able to glean specified testing by an independant lab" and environmental light exposure of "450 and 500 lux - intermittently - for twelve hours" - as an arbitrary value - more or less equivalent to "hanging on the average wall".
I just checked my studio walls with my Gossen Ultra Pro - set on "lux" and (10:00 AM - sunny day otuside) I have observed values ranging from 45 (shadier places) to 18,000 lux (sunlight streaming through window) - with an average of 450-500 - so the testing parameters seem to be somewhere near to reality - but -- there is no indication of the spectral composition of the interior light. Interior lighting has little UV - filtered out by "ordinary" glass.
Interesting to note that Ilford has a number of protecting laminates for applying over the emulsion to increase resistance to fading.