A Line can be straight, curved or contain a mixture of both straight and curved segments. A line must have a start and an end so it cannot be filled. (Although you can convert a line into a shape which can be filled.) You can apply a thickness, color, transparency and brush pattern to a line as well as line ends and patterns. When the two ends of a line are joined the line can be filled and is referred to as a shape. If a line has a fill applied to it, the fill will only be visible when the ends of the line have been joined. For more details, see Drawing lines.