At the right of the brush option bar, you will see an icon that looks something like a pen with a curving line behind it. If you click this icon, you will give your brush the ability to simulate an airbrush. The airbrush will deliver a softer stroke that can appear faded or dark depending on how long you hold your mouse button down over the canvas. A quick stroke can have a different effect than a slow steady stroke. This colour intensity of the stroke can be controlled with the Flow slider.

 

At the right side of the options bar, next to the air brush, you will see a Flow field with an associated slider switch. The slider can be accessed by clicking on the small arrow next to the flow value field. The flow controls the intensity of the brush effect. If the flow is set to a low value, the brush will take longer to apply its colour to the image canvas. A single click with the flow set low will apply a somewhat faded dot. A single click with the flow set high will apply a strongly coloured dot. As you hold your mouse button down, the colour will gradually intensify depending on the flow setting.

 

 

Above are three dots, each created from a single click with a brush set at 30 pixels wide and 100% hardness. For the first dot, the flow was set at 10%, for the second the flow was set at 50%, and for the third and final dot, the flow was set at 100%.

 

Airbrushes can be used effectively to apply light and shadow to an image, often through a mask of the type discussed in lesson 2.4 on adjustment layers.