Each of the five noble gases used to make luminous tubing -- neon, argon, helium, krypton and xenon -- have a distinctive color when pumped into a clear tube and electrified:

Neon		bright orange
Argon		pale lavender
Argon with mercury		bright, light blue
Helium		hot peach
Krypton		pale, silvery white
Xenon		pale, silvery blue

The tube may be clear, colored or phosphor coated. Various combinations of gas, glass and phosphor produce over 200 colors. The diameter of the tubing and the kind of transformer used to power the units also create subtle variations in hue and intensity.

Only the brightest gases -- neon and argon with mercury -- are used in commercial sign production, but artists and designers who do not exclude the dimmer gases may avail themselves of a palette of over 200 colors.

©2001 Luminous Artworks. All rights reserved.