Paint Normal: DrPaints over lines and fills on the same layer.

Paint Fills: Paints fills and empty areas, leaving lines unaffected.

Paint Behind: Paints in blank areas of the Stage on the same layer, leaving lines and fills unaffected.

Paint Selection: Applies a new fill to the selection when you select a fill in the Fill Color control or the Fill box of the Property inspector, the same as selecting a filled area and applying a new fill.

Paint Inside: Paints the fill in which you start a brush stroke and never paints lines. If you start painting in an empty area, the fill doesn’t affect any existing filled areas.

The Brush tool is especially well suited for artwork created using a drawing tablet