Glow tape

[derekleffew]

From Glow Tape from Rose Brand :

Glow tape has a non radioactive chemical light source incorporated into a flexible vinyl film that glows in total darkness after exposure to artificial or natural light. The chemical light source is designed to absorb energy from any nearby ambient light such as fluorescent lamps or sunlight. Once the source of extraneous light is removed, it immediately emits a light of it’s own. There is no limit to the number of times this product can be recharged. Three to ten seconds is the normal charging requirement. It can be used to spike stages for placement of scenery, mark exits in dark areas, mark light switches, and thousands of other applications. It's flexible vinyl backing is conformable and easy to cut to size. Also available in dots, corners, and arrows.

Available wherever theatrical supplies and tapes are sold. The most common size is a roll 1" wide by 10 yards long, which retails for about $10. A good way to "charge" the tape is with the flash of a still camera. Once charged, the tape should remain illuminated for at least 3-4 hours. As the tape gets older, it loses its ability to hold a charge and needs replacing. This is seldom a problem except on very long-running (over six months) shows.

The adhesive on most glow tape is not very strong, nor water impervious, so most stage managers will cover the glow tape with 2" clear cellophane tape., or secure it in place with a staple gun.

See also this thread: glow tape.