5 Industry-Changing Historic Signs and Techniques

IN CELEBRATION OF Signs of the Times’ 120th anniversary, we are traveling back in time not just through the magazine’s history but also the story of signmaking itself, one of the world’s oldest trades. Former ST editor, publisher and American Sign Museum (Cincinnati) founder Tod Swormstedt provides a highly informative tour of the signs on display at the museum that exemplify some of the most significant signmaking techniques of the past century and more, which pushed the entire industry forward and led to the signs we know and love today.

EDITOR’S NOTE: This post was updated May 4, 2026. Changes were made to the Neon, Opal Glass and Vacuum Forming sections.

Plastic

On display at the museum is one of the oldest fully plastic signs in the US, according to Swormstedt: a clamshell-shaped sign for Shell Oil Co., fabricated by Artkraft Sign Co. (Lima, OH) in 1946. The recognizable, modern-looking bright yellow-and-red sign is internally illuminated with lightbulbs as fluorescent technology was not yet used for signage at the time.

Neon

Experimentation with neon illuminated tubes had existed since before the turn of the 20th century, but they only became commercially viable in the late 1920’s after Georges Claude perfected the electrode and brought the technology to the US. This simple “GAS” neon sign, framed in a blue circle, dates back to the early 1930’s, Buffalo, NY.

Early Electric Advertising Signs

With several representatives at the museum, one of the earliest types of electric advertising signs consists of “stock” modular letter panels and decorative components, such as corners and scrollwork, that could be assembled into different signs for different purposes. The technology and this sign were created by Federal Electric Co. (Chicago) — now Federal Heath (Hurst, TX), which celebrated its 125th anniversary in March — with a patent dating to 1903.

Opal Glass

Flexlume Sign Co. (Buffalo, NY) is probably the best-known crafter of illuminated opal glass signs, with several Flexlume pieces on display at the museum dating to the 1920’s — though Swormstedt notes that a Canadian company received a patent (shown above) before Flexlume received theirs. To obtain their patent, a Flexlume representative submitted a letter along with a letter mold. All three items are now displayed together at the museum.

Vacuum Forming

Not too long after the introduction of plastic signs in the 1940’s, vacuum forming was developed to create large-scale displays and letters formed by wooden molds, such as these on display for a giant Coca-Cola bottle and the letter ‘O’ from “Kroger,” both by Tyson Sign Co. (Myrtle Beach, SC). In the vacuum-forming process, a hinged frame containing sheeted plastic is heated, causing the plastic to soften. The frame is lowered and draped over a mold. Then a vacuum sucks the remaining air from underneath the material to pull and form the plastic tightly around the mold, Swormstedt explains.