I\'ve always heard the term "Airbrush" when it came to photography. It was mostly used with models and magazine photography. I obvously now know that it is a digital procedure. It also annoys me when people still use the term "Airbrush" (sorry if you are one of those people).
Anyway, this got me thinking about the original airbrushing technique so I looked it up. Sadly this technique is so outdated that I could barely find any information.
I couldn't get my answer on Wikipedia, but I found it here.
Airbrushing is a technique employed to manipulate and enhance a photographic image. Previously if a photographer needed to alter their photos they would often use a compressed air powered airbrush to spray ink over masked prints to create the desired effect - a time consuming and highly skilled process requiring deft use of scalpel and a surgeons accuracy.
So before digital, people actually sprayed ink onto a photograph to make changes. I guess if you listen to the term, you could have probably figured it out, but I wanted to know.
These are obviously digitally enhanced (not by me), but cool.