Each color is the result of a different acid solution and process that creates a unique chemical reaction with the steel. I lock in the colors by neutralizing the acid and coating the etched steel with an automotive clear coat. This prevents the steel from corroding further and maintains the colors. There are no paints or dyes involved with this process.

The flags are 16 gauge Cold Rolled Steel. In other words, Mild steel that is ~0.06" (or ~1/16") thick. They are acid etched and coated with an automotive clear coat.