Home Photography Questions Cyanotypes are obtained by mixing ferric ammonium citrate and potassium ferricyanide. Is it possible to substitute Fe by Cu ions to produce red color?

Cyanotypes are obtained by mixing ferric ammonium citrate and potassium ferricyanide. Is it possible to substitute Fe by Cu ions to produce red color?

asked on March 24, 2020
Cyanotypes are obtained by mixing ferric ammonium citrate and potassium ferricyanide. Is it possible to substitute Fe by Cu ions to produce red color?

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