I tried it in a dip pen but would never put it in a FP due to acidity, caramelisation, solidification, and oils. I was going to leave it there, however it ended up having a sheen/shine that was unexpected so thought it might be of interest to inky recipe makers.
It didn't feather on Rhodia at all. It did bleed through but didn't seep on to the next page. It has a certain amount of permanence - wetting the page and rubbing across it with my finger caused an initial light smear but then the paper wore away before the 'ink' did.
The ristretto was too fluid really. I put some in a vial and added a xanthan concentrate I use experimentally for viscosity adjustment but it caused a synergistic reaction I've never seen before that turned it into a thick gel. Unexpected. Perhaps acacia might work better to increase viscosity if anyone ever got that curious.
edit: forgot to mention that the 'ink' is completely dry in these pics. That's sheeny/shiny dry ink.
Here are the pics I posted elsewhere.
Edited by Intellidepth, 14 March 2015 - 10:26.