The Original Glowing Blacklight Bubbles TEKNO BUBBLES may look and act like normal bubbles under ordinary lighting. But put them under a UV (blacklight), and they give a whole new meaning to “Glow in the Dark.” These bubbles are as glow-tastic as Tekno Bubbles Gold, only they glow a dazzling Blue under UV Blacklight. For best results, use with a blacklight at 365 nm wavelength. Most newer LED black lights shine at 390-400 nm. Tekno Bubbles will still glow under 390-400 nm UV light, but with diminished brightness.