I’ve seen some reviews of this ink that have been less than positive but I quite like it. It needs a broader nib to bring out the best of it (as do many J. Herbin inks) but, as its name suggests, this is a very stately green.
Here I am doodling the Inkling.
You can find some more reviews of J. Herbin Vert Empire on Pennaquod.
That’s much darker than it comes from my Art Pen F, but it’s a lovely ink. The shading quality reminds me a little of Alt Goldgrun.