\anchor free_borders_anchor
<h2>Sew free borders</h2>
-This functionality allows you to unite two free borders of a 2D mesh.
+This functionality allows you to unite free borders of a 2D mesh.
+
+There are two working modes: \a Automatic and \a Manual. In the \b
+Automatic mode, the program finds free borders coincident within a
+certain tolerance and sew them. Optionally it is possible to adjust
+the found free borders before sewing. In the \b Manual mode you are to
+define borders to sew by picking three nodes of each border.
\image html sewing1.png
In practice the borders to sew often coincide and in this case it is
difficult to specify the first and the last nodes of a border since
they coincide with the first and the last nodes of the other
-border. To cope with this, manually \ref merging_nodes_page to fuse
-each pair of coincident nodes into one.
+border. To cope with this,
+\ref merging_nodes_page "merge" coincident nodes into one
+beforehand. Two figures below illustrate this approach.
+\image html sew_using_merge.png "Merge coincident nodes which are difficult to distinguish"
+<br>
+\image html sew_after_merge.png "After merging nodes it is easy to specify border nodes"
The sewing algorithm is as follows:
<ol>
