I just read a post from KORAKS in this forum on how to make a cyanotype turn black into iron oxide, and remembered an experiment I did two summers ago. I was experimenting with sodium sufide, my favorite toner for silver prints, and though what would that do to a cyanotype? Would we get ferric sulfide (mars black)? So I slipped an old cyanotype into a very dilute sodium sufide solution, and it immediately turned an gorgeous deep black color with better tonality than I've ever seen. I was very excited by this, so put a bunch in, then washed and dried. During washing, the tone was reducing a bit. After drying, the black tone had disappeared and turned into the yellow tone that we get from bleaching a cyanotype, and could be toned in tannic acid the same way as after normal bleaching. I think tinkered the next few days trying to find a way to fix that beautiful pure black toned image to no avail. I tried acids, bases, and even hypo, and nothing worked. The toned image was obviously not ferric sulfide, which is very stable substance. What was it? Can it be fixed? It was obviously oxidized.
Comments and suggestions very welcomed.
Comments and suggestions very welcomed.