As I was developing a few 8×10 which were waiting for a while the other day, I found this one which I haven’t yet printed. Again coffee toned.
Cyanotype print from 8×10 negative
As I was developing a few 8×10 which were waiting for a while the other day, I found this one which I haven’t yet printed. Again coffee toned.
This is awsome. Does the coffee toned neutralize the blue color ? Is it its role ?
I would love to have the time learning this !!
Best,
Jérôme
Not sure how the toning actually works. It basically taint the paper and got the blue replaced with new tones. I hope you can answer that question from a chemical point of view during the next workshop (finger crossed for December).
So after a quick search, it seems this is a reaction between the tannic acid and the iron.
In this discussion, it is described what chemical reaction happens.
https://www.photrio.com/forum/threads/chemistry-of-tea-toning-cyanotypes.62920/
Very interesting.