A photograph of my daughters printed on Kodak RC paper in the early '90's. Seen clearly in the upper right is the
unwanted deteriorating effect known as bronzing.
©PN Parsons
This past summer ago I decided as a project to print a selection of 35mm family negatives for posterity but was flip-flopping on whether to print on my favorite paper (Ilford RC) or to use a fibre-based paper as recommended by paper manufacturers when archival longevity is of importance.
The above photograph was originally printed on 11x14" paper, matted in a passe-partout frame and hung in a hallway near a north facing window for several years.
I had begun to notice the slowly increasing presence of bronzing (a yellowish stain) about three years ago and was aware of it being a rare bugaboo with RC paper but this was the only photo of mine which had been effected.
Thinking maybe there might be technological improvements to resin-coated black and white papers in recent years I sent an email to Ilford in which I described the bronzing effect in my picture. A short time later I received a reply from Ilford Canada saying bronzing was a rare occurrence in both RC and fibre paper and was most likely caused by improper fixing or washing, chemicals leaching from framing materials, display environment etc.
I am embarrassed. When I took the frame off the wall to take a picture for this blog I noticed the photograph was not on an Ilford paper but made on one of Kodak's. I remain an idiot. Apologizes to the nice person at Ilford.
Anyhow when I do get around to editing and printing the negatives I plan to use fibre paper and now recommend to the darkroom printer to use fibre-based paper, fresh fixer along with a good washing and selenium toning for your archival work. After you are gone you don't want your children to say 'Dad's pictures are turning yellow!'
For the record here are the highlights from the Ilford Canada:
Bronzing is an effect that shows yellowing or more typically when worse - as a metallic silvery or gold-like appearance on the surface of paper. It can affect RC and FB papers - but is slightly more common on RC papers.
It takes time for it to show - it never arises after paper has been processed. Sometimes it might arise within several months, but other times - it literally could take several years (as in your instance).
It can show in small/localized areas or overall, but typically it always starts in a limited area, and then it spreads. At its worse - as mentioned above, a print can look like its got a silvery, or bronze or gold - mirror appearance.
Its presence is due to a print not being archivally stable - and the print degrading. ie The effect arises if a print hasn't been fixed effectively - or washed for long enough (to remove the residual silvers etc). The image can then get attacked (even if behind glass) to oxidizing agents such as peroxide, paints, varnishes, air pollution.
If a print hasn't been processed correctly and is not archivally stable - I've certainly known bronzing arise such that a print has remained totally good/normal in a glass frame for 1- 10 of years, but then suddenly shows the problem when the room the picture is hung in - has been decorated (paints, glurs etc), or new carpet is laid (glues etc), or a floor has been varnished. It can happen very speedily after those pollutant triggers.
Once the effect has arisen with a print, its not possible to reverse it unfortunately.
