J.Herbin Phosphorescent Ink- 30ml

The ink is clear under normal light but in the dark is has a wonderful glow.
"It is the ink of lightning bug. Place it close to a source of light, invisible, it will appear at night."
Please note that because the ink has residue in it, it is unsuitable for use in fountain pens and is best suited for steel nibs, glass or quill pens, calames and brushes.