I found, at the bottom of my medicine cabinet, an old (over 30 years old) bottle of aqueous eosin. It’s a bit too transparent for my taste to be used as is, but here’s an example of the (amazing) result when you drop a bit of eosin in iron gall ink still wet.
![](https://benoitfuret.com/wp-content/uploads/2023/01/writeright.jpg)
I’m fascinated by the fluorescent green, it’s quite unexpected.