| 1) | Press the Spline button in the toolbar. |
| 2) | Click the cursor in the drawing area where you want the spline to begin. This places the first point for the spline. |
| 3) | Add new breakpoints by clicking in the desired positions. Note that while the spline is being drawn, it will be drawn with sharp corners like a polyline. |
| 4) | Complete the spline creation by double-clicking the left mouse button where you want the end of the spline (you can cancel the creation any time by pressing right mouse button). |