exotic color, richly pigmented
The J. Herbin company, begun in 1670, took part in the great exhibitions, including the London show of 1829 where it received a medal for the exceptional quality of its inks and seals.This invisible ink becomes blue when you warm the paper and disappears when the paper is cold. Never mix the inks and always rinse your nibs, ink pot or fountain pen before using a new color.

(1) Bottle, J. Herbin Specialty Ink — Invisible Ink