Selecting a Brush
Many drawing tools also work together with brushes, which affect the application of paint strokes. Obviously, when using a paint brush, the brush you select determines the size of the brush strokes. Also, if you create an outline of a rectangle (a stroked object), the outline's thickness will depend on the size and shape of the selected brush.
To select a brush:On the Paint Controls panel, select a brush from the Brushes palette.
For information on customizing brushes or selecting different brush palettes, see Brush Controls.