Skywriting is a unique variation of aerial banner ads. The latter is done by printing the ad on a long banner or on a billboard and then dragging it through the sky over a crowd. Skywriting, on the other hand, is actually using the sky as the canvas on which to write the message.

How does Skywriting work? A paraffin oil is injected into the exhaust of the airplane at controlled times, causing a white smoke to form. As the plane flies in various formations turning on the oil spray, letters of a message are formed. The letters are formed from 7000 to 17,000 feet up, and are at times a mile tall.

A variation of this technique is called skytyping. This is done by five or six planes flying in parallel across the sky on a clear day. A computer, located on the lead plane, is programmed with the desired message. As the planes fly, the computer decides when each plane is to release the oil into the exhaust and for how long. The result is a series of dots and dashes in a straight line. Each dot or dash makes up part of a letter, written with disconnected lines. Skywriting messages are made by one or two planes with solid lines, but skytyping messages are made by five to six planes using dots or dashes of smoke.

Each technique has its advantages and disadvantages. Sky typing allows the message to be made much quicker and thus can be longer and read in its entirely. A single plane skywriting takes 60 to 90 seconds to form one letter. The letters with skytyping are formed in a few seconds. This means the entire message is still visible when it is finished. A long message in skywriting might mean the first letters have drifted away by the time the message is completed. Also faster work means people don’t get bored waiting for a message to be completed.

Skywriting demands a skilled pilot who can maneuver a plane in every direction. He must also be somewhat of an artist to make the message uniform so it can be read. The skytyping pilots only need to fly in a straight line. The computer does all the deciding when to make the white smoke.

On the other hand, skywriting can be done with one or two planes which is much cheaper than hiring a whole fleet of planes to make one message. Geico insurance is famous for the skytyping messages, forming their name with dotted lines in the sky.

Both methods have some advantages in common. First, the message is environmentally friendly. The paraffin smoke is harmless. Second, the preparation is simple. There is no need to print an expensive sign to be dragged behind a plane. The pilot just plans how to fly the letters of the message in his skywriting or programs the message into the computer for the skytyping. The message can be repeated or changed as the client desires.

Skywriting and typing have another advantage in common with aerial advertising. All use the canvas of the sky to present their offer to a large attentive audience without competition. The skywriting cost per new customer reached has proven to be well worth the expense.