First you’ll create something using Live Paint to get a feel for what the feature is all about. Then we’ll discuss how the feature works, and at that point, you’ll better understand how to use it in a meaningful way. Select the Line Segment tool, and draw two parallel vertical lines and two parallel horizontal lines to create a tic-tac-toe board. Don’t worry if the lines or spacing aren’t perfect—for this exercise, you just want to make sure the lines cross each other.

Select the four lines, and select the Live Paint Bucket tool. As you move your pointer over the four paths, the paths become highlighted. Click once to create a Live Paint group. Now, choose a fill color (a solid color, gradient, or pattern) from the Control panel, and move your pointer over the center area of the tic-tac-toe board. The enclosed area in the middle becomes highlighted in red, which indicates an area that you can fill with color. Click once with the Live Paint Bucket tool to fill the highlighted area.

The resulting behavior is very Photoshopesque—you’ve filled an area that is enclosed on all sides, but you didn’t fill an actual object. Choose the Direct Selection tool, select one of the paths, and move it just a bit. Notice that the color in the area updates to fill the center. If you move one of the paths far enough to the side so that it no longer touches the other paths, you’ll find that the fill color disappears, because there is no longer an enclosed area to fill.