This waterproof gilding glows under blacklight. Apply Blacklight Gilding the same way as you apply Harquus,  "Inked" or Scheherazade Gilding.   You can apply it at the same time as the henna paste, and the blaclight glow will be there as your henna stain darkens.

The color lasts several days, depending on care and skin type.  The blacklight luminescence may last for over a week, even after the pigment is gone. The different daytime colors glow about the same color under blacklight. The white glows the brightest.

 The gilding is waterproof, but may be removed with baby oil.  Clean your brushes with 99% isopropyl alcohol.