Developed and perfected in Europe, porcelain enamel techniques brought new possibilities for the production of high quality, durable signs. During fabrication, a powdered glass composition (frit) is applied in layers to a metal base. The lettering is carefully stencilled on by hand. The sign is then fired in a kiln, which causes the glass and metal to bond.
Porcelain enamel is more than a surface paint. When heated to high temperatures, metal becomes porous. The liquid glass seeps into the small openings, and the metal and glass become structurally one. Vintage signs made with porcelain enamel maintain this bond and, therefore, their quality.
In the late 1890s, porcelain enamel signs made their way across the Atlantic to the United States. The techniques were quickly adopted by artisans and fabricators. They experimented with bold colour and different techniques to create new designs. Because of their durability, porcelain enamel signs were a boon for outdoor advertising. Resistant to rain, snow, wind and sun, these signs were industrial strength. Above all, porcelain enamel signs were colourful and stunning, a perfect way to catch the eye of a passer-by.
WWII brought scrap metal drives. Across the world citizens were encouraged to contribute scrap metal and other materials to help the war effort. Pots, pans, iron fences, all metal was game–including porcelain enamel signs. The scrap metal was melted down so it could be transformed into tanks, ships, and weapons. By the end of the WWII, the production of porcelain enamel signs had seen its peak. The dye was cast, signs of this material were to become the collectable antique signs of the future.
After WWII, sign manufacturers began to experiment with and use other materials. The plastic industry started to grow by leaps and bound and new commercial uses for plastics were rapidly being introduced. Metal sign fabrication shifted course. Due to the high cost of manufacturing porcelain enamel signs, steel metal bases were replaced with tin, a much thinner material. The glassy hand-stencilled porcelain enamel surfaces gave way to enamel paint, which does not have the bonding properties of porcelain enamel. While tin signs lowered the bottom line and contributed to more efficient mass production, the overall value of the signs diminished. Tin signs are not as durable as porcelain enamel signs and, as a result, they are a more disposable version of the now sought-after vintage enamel signs.