The artist used a company called AirSign, who fly five aircraft in formation to write messages as a dot matrix: http://www.airsign.com/skywriting.php http://www

The artist used a company called AirSign, who fly five aircraft in formation to write messages as a dot matrix: http://www.airsign.com/skywriting.php http://www.airsign.com/skywriting.php You can read more on the artist's website here: http://ishky.com/pi/ http://ishky.com/pi/