LED Channel Letters. Channel letters are typically illuminated with either neon or LED (light emitting diodes). Neon was previously the primary illumination media, but in the past few years LED has become the most common channel letter lighting source. LED Channel Letters. Channel letters are typically illuminated with either neon or LED (light emitting diodes). Neon was previously the primary illumination media, but in the past few years LED has become the most common channel letter lighting source.
