"I am trusting to serendipity something happens"~ Jane B :printing nature

With regards to "what is the composition of the rusted bits you used in your eco processing bath"   fellow Printing Nature enthusiast responded "I am trusting to serendipity something  happens."
A blog post ago I mentioned serendipitous affirmation, by virtue of past outcomes I too still strongly believe to discover beautifully unpredictable interactions between plant material, substances present in the bath water supply and iron {ferrous sulphate} with evidence there of if it rusts then it most likely includes iron. 
My theory is that the plant material simply provided the acids necessary for the colour to bond with the substrate {cloth} being dyed. In other words, the plant was acting as the mordant for the colour from ...[in the above instance "from" iron in the rusted bits] ~India Flint the book Eco Colour  

examples from my studio work:
 The blackest color is the result of adding rusty bits and black walnuts in the processing bath. 
Appearance of black is present on the exterior most bundle surface, The bundle exterior is the area that comes in direct contact with the iron particles, functioning much like a filter or sieve during the "boiling the bundles" process phase.

here is an example of instance where the iron collected around leaves closest to bundle exterior 

example of "boiling the bundles" phase 

the given marks will vary with color determined by "what is the content of your rusty bits" and what ever else is proactive in the bath water. It is perhaps the most telling characteristic of "bundle processed prints made with nature" 

was a beautiful foggy green start of my day I really enjoyed the morning doves coo and a beautiful reflection on the journey. With that I wish you a beautiful rest of your day