Common line properties
In most cases the property you want to change is the line’s style (solid, dashed, invisible, and so on), its color, or its width. These options are all available from the Line and Filling toolbar.
You can also edit these properties from the Line dialog, where you can also change the line’s transparency. The figure below illustrates different degrees of transparency.
The vertical lines have different levels of transparency (0%, 25%, and 50%).