Tire lettering is the practice of putting, or drawing visible letters on the sidewall of an automobile's tires. In modern usage, the lettering is often big car brands or tire brands names, with custom lettering being a much smaller niche of that. It can also refer to other after market customizations to the side wall of the tire, such as the "white wall tire" look, but any color of the spectrum is available now, including "rainbow wall tires".