Skywriting is the art of using an airplane to create messages in the sky with chemically produced smoke. There are two basic kinds of skywriting: standard and skytyping.

In standard skywriting one airplane produces a continuous stream of smoke and it maneuvers in the sky to create a message that can be seen for fifteen to twenty miles (24 to 32 km) in all directions. The pilot, who has a diagram of the message in the cockpit, must plan the mission carefully because the writing is done upside down and backwards in relation to the pilot's position. He or she flies up to at least ten thousand feet (3,050 m) to avoid most of the convection currents that could quickly destroy the message. The pilot maintains a speed of 150-175 miles per hour (240-280 kph), flying into the wind to keep all the letters in the same spatial relationship. Some letters are more difficult to skywrite than others because they require precise timing and maneuvering: N, M, W, and S are especially demanding.

Skytyping uses a formation of airplanes that release short, individual puffs of smoke to create letters. It resembles dot-matrix printing in this regard. On the ground a punched piece of paper tape is prepared with the message. The tape, on a reel, goes into a machine in the lead plane. This machine reads the tape and translates it into radio signals and sends them to receivers in the other planes (usually four) to govern the formation of letters that can be five hundred feet (152 m) tall and a finished message that can stretch five miles (8 km) in length. One flight can cover a whole state with several skytyped messages.

In 1986, a new skytyping method was introduced that only requires one plane: the plane tows a three hundred-foot (91 m) cable with seven cylinders attached. These cylinders, which containing a fogging substance, are turned on and off by a computer in the cockpit. All types of skywriting usually utilize the same kind of smoke. Specially formulated petroleum oils containing paraffin additives are sprayed onto the aircraft's hot exhaust pipe. Up to sixty gallons (227 l) of oil can be used in one day of skywriting. An innovation in skywriting is colored smoke, created with the addition of light foam plastic or oil-soluble dye.