What Gases Are Used in Neon Signs?

Neon signs mainly use neon and argon gases, though mercury can be used to provide a broader range of colors.

This guide breaks down which gas does what, so you can pick the right one for your sign.

WestAir supplies neon across California and Arizona.

Neon Gas Creates the Iconic Red-Orange Glow

Pure neon gas is used for the classic red-orange glow.

Here’s how neon produces its warm glow:

1. Electric current excites neon atoms: when voltage is applied to the electrodes at each end of the tube, electrons flow through the gas, colliding with neon atoms.
2. Energy absorption: these collisions transfer energy to the neon atoms, pushing their electrons into a higher energy state.
3. Light emission: when the excited electrons return to their normal state, they release energy in the form of visible light, producing neon’s signature red-orange glow.

Fun fact: Neon lighting was first publicly demonstrated in 1910 by French engineer Georges Claude at the Paris Motor Show. The first commercial neon sign was sold in Paris in 1912.

Neon is efficient. A small amount of gas produces a bright display, which keeps costs down.

Neon also performs well in cold climates. It doesn’t rely on mercury vapor, so it stays bright when temperatures drop.

Further Reading: What Is Neon Used For?

Mercury and Argon Work Together for Blue Light

Mercury vapor produces blue light when combined with argon and the appropriate phosphor coatings. Argon is a key piece of the puzzle because it has a low striking voltage—this helps initiate the electrical discharge.

Argon can serve as a primary gas in some signs, but it rarely works alone.

Argon’s real value is versatility. Combine it with mercury vapor and different phosphor coatings, and you can get anything from bright green to soft pink.

The tradeoff: argon-based signs can get sluggish below about 45°F, which means dimming or flickering. If your sign lives outdoors in a cold climate, neon gas is the more reliable pick.

Beyond the Basics: Specialty Gases for Unique Effects

Besides common gases, you can use specialty options to create distinctive effects for your signage needs:

Krypton

Krypton emits a whitish-yellow to bluish-white glow when electrified, and it is particularly useful in creating subtle effects. It’s even used in airport runway lighting due to its reliability and distinct appearance.

Xenon

Xenon creates a bluish or lavender glow, and is often chosen for high-end displays where unique color combinations are desired. If you’re going for a premium look, xenon is worth considering.

Helium

Helium emits a pinkish-red glow when ionized, but its light is much fainter than neon’s and is rarely used in commercial signs.

Mixing Gases and Techniques for Custom Effects

You can combine different gases and techniques to create specific colors and effects in your neon signs. Here are the factors that contribute to the end result:

• Glass color
• Phosphor coatings
• The pressure inside the tubes

With the right combination of mercury vapor, noble gases, and phosphor coatings, you can hit virtually any color on the spectrum.

Find the Right Gas for Your Needs

The right gas depends on the color, intensity, and mood you’re after. Some signs need just one gas; others layer gases, coatings, and glass colors to fine-tune the result. Start with the look you want, then talk to your supplier about how to get there.

Further Reading: How Long Do Neon Signs Last?

Nick Vasco

Nick is an experienced B2B writer who brings his skill for crafting clear, easily digestible content to the industrial gas space.