Gelly Roll Moonlight pens are the unique opaque gel roller pens that "glow" under "UV light" (Blacklight source).

Your words will dance in the Moonlight with these 10 bright and vivid colors. Great on either white or black paper surfaces, the bold line will not bleed through on most papers. Writes even on vellum papers! Provides a "paint-like effect" in photos, craft projects, journals, scrapbook pages. 1.0mm ball size produces a rich 0.5mm bold line. Permanent, waterproof and fade-resistant on many surfaces.
* Fluorescent colours can fade if exposed to direct sunlight.

Quote product reference: G00908