Modifying a Line Style
In a diagram, you can modify the style of each line.
You can also modify the style of several lines at once.
For each line, you can modify:
its style:
free or orthogonal
closed: enables to draw an irregular polygon, which can be filled with a color or a pattern.
perspective: enables to adjust the right angle in diagram with object in perspective.
its appearance:
curved or straight
rounded or right angles
simple or double
weight
dashed or solid
its color
its extremities:
line ends covered or not by connected elements
with or without shapes
(with shape) each shape color
To modify a line:
1. To modify several lines at once, use the [Ctrl] key to select the lines.
2. Right-click the line and select:
the line style for a simple style modification
Colors and Borders for an advanced modification
The Graphical Options window opens.
*To modify a single aspect of the line, you can use the quick access of the shape editing bar of the diagram.
3. In the Lines section, use the drop-down lists to modify the line:
its Style
its Extremities
its extremity style (Start style and End style)
*If you do not want a shape at the end of the line, select the straight line.
4. (if needed) In the Lines section, select:
Rounded angles
Curve
Double lines
5. In the Line section, use the drop-down list to modify the line:
its Color
its Style
its Thickness
6. (Line extremity with solid shape style or closed line style) In the Fill section, define the shape color.
Examples of lines 
Orthogonal line, rounded angles
Perspective line, rounded angles, start style: empty diamond, end style: circle filled with orange