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#11
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B/W print turned mottled gold
I use a lot or Gekko RC and haven't seen this happen I do
have a Polycontrast !!! contact sheet in hand that has started turning, I know for a fact it was inadequately fixed (old fixer) and washed. It was done where I work and the fixer was always left in the tray. Prints I do at home in my darkroom do not exhibit this issue since I process and wash one print at a time. Nicholas O. Lindan wrote: "Jim Stewart" wrote after about a year, the black areas turned an ugly mottled gold color. I used Ilford chemistry and Mitsubishi Gekko paper. This happens to RC paper - the reason for it is a matter of debate. Titanium dioxide in the paper reacting with UV light is one current suspect, sulfur from pollution or the mount material is another. The history of RC materials is one of problems followed by Kodak/Agfa/Ilford/xxx claiming 'we have fixed the problem' followed by either the reemergence of the old problem or the creation of an entirely new problem. I greet any explanation or solution with suspicion. Agfa RC was very prone to bronzing. I haven't seen any on Ilford RC but that may be a matter of luck/time. To keep it from happening again you might try using Ilford paper. Err on the safe side: use fresh fixer for 5 minutes, a hypo eliminator, wash for 1/2 hour. There are all sorts of fast processing methods but the old methods are known to not contribute to the problem. If the picture is in a frame then make sure you use acid free board for the mat and mount board - "4-ply 100% cotton museum board" is considered the safest: the core of the board should be pure white, not grey. |
#12
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B/W print turned mottled gold
By accounts I have reference to; that is personal conversations and
experience some RC Papers from 1980's and before do have this issue. Especially machine printed RC silver based papers- Like Agfa RC's. Not fixing properly always can produce the issue: bronzing, the silver will migrate out to the surface if the fixer does not seal the top most silver molecules, having an airspace between paper surface and glass also seems rather important. Its probably also a result of how certain papers were once made with regard to the placement of the silver layer within the emulsion. In article , "Pieter" wrote: I don't know that RC has a history or a current problem like this, but I think the suggestions offered below are excellent. I immediately thought of incomplete fixing or incomplete washing, but mounting materials could also be a problem as suggested ny Nicholas below. I have never had a problem myself, but I frequently test fixer and fix with a timer then use an effective print washer. Hypo eliminator would remove any fixer left on the paper. I have only seen strange coloration and fading occur as the result of chemical contamination, usually in group darkroom settings. "Nicholas O. Lindan" wrote in message ... "Jim Stewart" wrote after about a year, the black areas turned an ugly mottled gold color. I used Ilford chemistry and Mitsubishi Gekko paper. This happens to RC paper - the reason for it is a matter of debate. Titanium dioxide in the paper reacting with UV light is one current suspect, sulfur from pollution or the mount material is another. The history of RC materials is one of problems followed by Kodak/Agfa/Ilford/xxx claiming 'we have fixed the problem' followed by either the reemergence of the old problem or the creation of an entirely new problem. I greet any explanation or solution with suspicion. Agfa RC was very prone to bronzing. I haven't seen any on Ilford RC but that may be a matter of luck/time. To keep it from happening again you might try using Ilford paper. Err on the safe side: use fresh fixer for 5 minutes, a hypo eliminator, wash for 1/2 hour. There are all sorts of fast processing methods but the old methods are known to not contribute to the problem. If the picture is in a frame then make sure you use acid free board for the mat and mount board - "4-ply 100% cotton museum board" is considered the safest: the core of the board should be pure white, not grey. -- Nicholas O. Lindan, Cleveland, Ohio Darkroom Automation: F-Stop Timers, Enlarging Meters http://www.darkroomautomation.com/index.htm n o lindan at ix dot netcom dot com -- Reality is a picture perfected and never looking back. |
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