Skywriting is a form of aerial advertising where pilots use specially designed aircraft to create words or images in the sky. This is achieved by releasing a vaporized substance, usually a mixture of fuel and oil, which forms visible smoke trails as it disperses in the air. Skywriting is often used for promotional purposes, special events, or personal messages. The practice began in the early 20th century and gained popularity during the 1920s. It requires skilled pilots who can maneuver the aircraft precisely to form letters and shapes. Skywriting can be seen at fairs, festivals, and even during airshows.