The boundaries of a polygon object can overlap or touch, but they cannot cross. When you pick points to draw a boundary, a point will be rejected if it causes the boundary to cross itself or if it crosses a previous boundary created by the command.
You select the fill color and pattern used to fill polygon objects. For color, you can choose from a variety of colors including true colors and colors from imported color books. For pattern, you can choose a predefined hatch pattern, a simple line pattern of your own design, a more complex hatch pattern, or a solid color. You can also create a gradient fill, which uses a transition between shades of one color or between two colors. Gradient fills can be used to give the appearance of light reflecting on an object.