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Thursday, April 26, 2012

I am back again to the coffee and color

One of my first failures with Caffcol I

The leitmotiv and primary motivation of this blog was and is to find a coffee-based developer for C41 process. I am not sure if it will work 100%. I have experimented two approaches: the first one is to add a little CD-4 to normal caffenol and develop as usual C41, using coffeee, instead of the hydroxilamine; the second is a two bath developer where the first is just CD-4 with a preservative and that can be used several times, and the second bath is a mixture of sodium hydroxide and coffee so that the pH is about 12. The first approach gaves more vivid colors than the second but both work, temperatures may have an influence in the final result.
But I didn't give up trying to develop without the expensive and rare CD-4, only available in a complete kit that costs a lot and where some bottles only have sodium carbonate or EDTA and normal fixer.
If I succeed in developing without CD-4, this will be «gold over blue» like it is said here in Portugal when something is very good.
When I started searching about color development, I found many references to para-phenilenediamine and had no idea about what that was, and where it exists in common products. I found out that it is used in hair dyes, then I found out that some people could make use of this component of hair dye to make a sort of color pictures, very «artistic» ones but not really color photos.
Then I learned that CD-4 is not para-phenilenediamine but a sulfate of a derivative of that substance. Further I learned that there were other CD-N substances used in other color processes, all very complicated for a non-skilled in Chemistry like me.
But, one think is theory, another is practice. Theory without practice is worth nothing, practice without any theory is dangerous. So I must be careful doing experiments and not just mix things and see, some dangerous substances may form and bye bye, Henrique!
But if I go on reading and experimenting, maybe I will achieve the goal.
I hope!

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