The Type A-2 leather flight jacket is an American military flight jacket originally invented and developed for and closely associated with World War II U.S. Army Air Forces pilots, navigators and bombardiers, who often decorated their jackets with squadron patches and elaborate artwork painted on the back. Sometimes casually referred to as a bomber jacket, its original designation was "Jacket, Pilot's (summer)", and its wartime usage was limited neither to pilots nor to bomber crews.
In WWII almost any kind of paint that could be used was used. Enamels if they could get it, lead based aviation paint, oil paint… whatever the ‘artist’ could get their hands on. Some squadron artists could only get their hands on yellow airplane paint, so the artwork on the jacket was done in yellow. As troops settled in, painting flight jackets became a cottage industry for the local artisans. Since some of the paints were not meant to be used on leather, they rubbed off, flaked off, and faded.