Airbrush is a painting method simulating traditional airbrush techniques. The Airbrush exists as a regular tool in Photoshop 6; in the later versions it's available as airbrush mode for various painting tools.

• In the Toolbox, select the Brush or some other painting tool.
• On the Options bar, activate the airbrush mode.
• Set flow amount, that is how quickly paint is applied by your tool.
• Paint.

Note that the slower you move your tool, the more paint you put on the image. The paint flows even if you simply hold down your mouse key without moving the tool (movie).