The Airbrush Tool

1. Click the airbrush tool in the tool box. To change the size of the spray pattern, choose a size from the options below the tool box. To choose the spray color, click a color.
2. To spray, drag the mouse pointer. Use the left mouse button to spray with the foreground color, or use the right mouse button to spray with the background color.

Assignment: Spray a border around the edge of your picture