Quote Originally Posted by Jadedoto View Post
Isnt water a main component of concrete? How would that affect it, since washing away unexposed compounds is half of what makes cyanotype work?
Yes. As cement sets - not actually concrete - water is bound by the various ferric and ferrous compounds into pretty tightly held molecules. (*)

But I don't think that any of the UV sensitive reducable ferric salt is going to be bound to water. After all, once you coat a piece of paper you let the layer dry before exposure. So the molecules of sensitizer will be different than the molecules of the structural support.

Of course, I could be wrong!!

Clearly this is going to take some research.

*Decades ago a technician's knowledge of Portland cement's properties in presence of various contaminants was important in my work. But the vast majority of that knowledge is long gone now.