Using Masks and Layers—Painting, Filling, and Color Tools - GIMP 2.6 for Photographers: Image Editing with Open Source Software - page 292

Figure 3.108
The finished mask.
The mask was
adjusted with the
Paintbrush and
Eraser tools.
Figure 3.109
The finished selection.
The tail and back of
the lion have been
retouched using the
Clone tool. This fine
touchup work is done
in selection mode
because this mode
preserves the lion's
contours.