Line styles control how the outline of the shapes is drawn. The default is a solid line. Available line styles are dotted lines, dashes lines and custom styles. To choose a certain line style, select the layer or the layers for which to change the style and choose the line style from the "Style" panel.
New styles can be created with the "Custom Style" button. A line style editor will come up that allows creating and editing of new styles. The predefined pattern cannot be changed. To apply a new style, select "More" from the style selection panel and choose the new style from the list. The custom styles are saved with the layer display properties.