Keith Tapscott.
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.....and a small (<1%) amount of a substance called "1-Phenyl-4-methyl-3-pyrazolidone".......
That indeed seems to be the case. The Australian MSDS for the Ilford / Harman Warmtone developer additionally mentions a significant amount of 5-10% borax, and a small (<1%) amount of a substance called "1-Phenyl-4-methyl-3-pyrazolidone", which according to this page is a developing agent too. According to Wikipedia, one of borax's uses is to buffer solutions at a certain pH (usually pH 8, just mildly alkaline, but I see also a mention of pH 9.2-11 for a buffer with borax and sodium hydroxide, so that may be possible too). Anyway, the Warmtone developer may not be more alkaline after all, but buffered at a slightly lower pH, more close to neutral pH, compared to the Cooltone and normal Multigrade developer. That would be in accordance with John's remark.
Of course, with pH being a 10log of H+ ions concentration, even a 1 step difference in pH, means 10x more or less alkaline hydroxide (OH-) ions in solution to participate in the development process, so even an apparently "small" change of pH from 10 to 9, could have a significant effect on developer activity.
By the way, the MSDSs of course also mention Hydroquinone as the actual developing / reducing agent in all the variants, I just didn't list it in the previous post, as it seemed logical enough and there aren't differences in the sheets (all mention 1-5%)
My recollection tells me that Zone VI studios had the paper manufactured by an unknown paper coating company in France when the original Oriental Seagull had an emulsion change back in the nineties.
Brian, are you trying to go from two papers to one?
- Thomas
Jeff, were you printing on a neutral tone paper for some time before you tried MGWT?
Warmtone papers get colder over time, they didn't before the Cadmium was removed from them. Some shift more than others but I noticed a very significant shift in the Ilford Warmtone I used last November compared to a year or so earlier.
The increase in contrast (apparent) in fixing is the clearing of the emulsion as the silver halides are dissolved, try it with some film processed in a white tray, switch the light on as soon as it's in the fixer, it'll look flat & milky then as it fixes the contrast increases.
Ian
The only trouble I have had with MCC is that when I have a flat neg and need to get the highest contrast possible, it hits the ceiling before the MGWT, which has close to a grade more contrast I would say. Not often necessary, but when it is, its everything. Both have closely matched surface sheens too - handy.
I would like to hear from those of you who have used MGWT with LPD, if any.
Jeff
Warmtone papers get colder over time, they didn't before the Cadmium was removed from them. Some shift more than others but I noticed a very significant shift in the Ilford Warmtone I used last November compared to a year or so earlier...........
Ian
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