Working with brushes

Lately I'm busy with something completely different. I'm trying to get more and more control with my prints. I know that in this area, control is considered a bad thing but I do not see anything wrong with trying to expand the boundaries.

I work with a palette of iron at different concentrations and with brushes I'm painting the leaves as I want and in this way I can choose what effect I will get with the same leaves. 

I discover a whole new world.  

It just make it so clear even while applying the iron which leaves are very sensitive to iron and can easily become very dark and how to control it in case I don't want the dark effect or which leaves resisting the iron and if you want any effect you really need to apply strong solution.

Which part of the leaf is sensitive and which part is not.

To which part of the leaf to apply the iron to get different effects. for example, only contours, more natural effect or more graphic effect, etc...

What is also nice is that my background stay almost clean from the iron. Which mean, if I want to dye the background with madder for example, the iron will not effect the purity of the madder shade.

So yes... I'm loosing spontaneity in my work with such a technique but I know I will find the balance again in the future.

For now, I'm very much into it and it is fascinating.