Neon signs are made of clear glass tubes bent into letters, shapes or whatever design and are filled with inert gas at low pressures. With a touch of an electrical current, the gas inside the tube glows.
The most commonly used gas is neon. Neon is a noble gas discovered by Ramsay and Travers in the 1800s. It is the second lightest inert gas and can be extracted from our atmosphere. Neon gas is often used in neon signs and gives a distinct bright red glow. Of course, they come in variety of colors, such as a purple neon sign, blue neon sign, green neon sign or almost any color. Even though they are called neon signs, other gas can also be used such as argon. Argon gives off a blue hue.
The type of glass and gas used determines the color of neon sign lights. With the basic knowledge that neon gas shines red and argon blue, neon sign makers can mix these two bases with colored tubes lined fluorescent powders to produce a number of colors. An example is to put red-glowing neon gas in a yellow tube to produce an orange light. Place blue-glowing argon in yellow tube and a green light is produced.
Commercial applications of neon signs can be seen in business signage and advertising media. With expert glass bending, practically any design can be produced. They can be small and simple as the open sign or the company logo. They can also be wide and intricate such as the ones seen in hotels and casinos. Neon signs can either have static or flashing lights. Programming the switches to turn on and off can produce animated neon signs.