About Black Light ...?

Question

Where can I purchase it ? Is there any special pen which is visible under it ?

Answer 1

You should be able to buy a UV lamp at any good electrical store.

Also available are UV bulbs and tubes. I'm sure you can find these items on the web. Anything that fluoresces under UV will glow in the "black light". Use of detergents that contain optical brighteners will cause the clothes washed with them to glow.

Answer 2

Hilighters will "glow" in black light.  Get one and have fun.