airbrush diagram

Yes it does. In physics, things push, they don't pull. Higher air pressure above the paint cup creates an unbalanced force with the low pressure created by fast moving air over the needle, pushing the paint down across the needle.

I did a project on them...

These links should give you more than info regarding airbrushes

http://www.howtoairbrush.com/airbrushs.htm

http://www.airbrushtalk.com/part1.htm

http://www.manifestartstudio.com/pdf_downloads_gallery.htm

http://www.arttalk.com/pdf/Airbrush%20Getting%20Started%20Booklet.pdf

-Fred

It's called a "venturi effect". It' works like a carburator on an engine. Or same as how a flute works. The fast moving air across a small hole will create a low pressure zone wich creates a vacuum into the hole. So the air rushing past the small hole makes a vacuum, which sucks the paint up and into the air stream.

Varrying the air speed and the relative hole size will alter the effect.

check here to see this effect on a carb.