You can set the stacking order of lines relative to other elements. For example, above or below artwork.
To change the stacking order:
On the Main toolbar, click Select.
If you want to:
Edit an internal line, on the Horizontal contextual menu, ensure Internal is selected.
Edit an edge, on the Horizontal contextual menu, ensure Pieces is selected.
In the 2D window, click the line you want to edit.
Go to the Context view, in the Actions section, at Order.
Adjust the order as required.
Click to put the line to the top.
Click to move the line up one layer.
Click to put the line to the bottom.
Click to move the line down one layer.