Feather and Bézier curves
The Bézier curve pen is the most complete tool, since it allows you to make paths that combine curves and lines. And then, in addition, they can be modified. In this case, work is not done by freehand, as with the pencil and calligraphic pen, but by making successive "clicks" on the paper. Clicking generates a line. If you click and without releasing the mouse button, it moves, a curve is drawn that will be wider the more you move the mouse. In this way we can combine straight segments and curved segments.
To end an open path, we have to press "return" on the keyboard. If we want a closed path, we will have to do a final click at the same point where we started our path.
Once the layout is done, we can always modify the nodes and redraw the curves. We can also convert round points to corner points, and vice versa, and include or delete nodes.