There are three methods:

• Select by type: Use this drop-down menu to select all contours traced with a single contour type; useful when you want to render a series of contours as a wireframe or a shell.
• Select All: Use this button to select all contours, regardless of the type.
• Single click: To select a single contour, click it in the tracing window.

Hide selected contours with the Hide Selection button to facilitate tracing. You may display the hidden contours again with the Show all hidden button.

Use this button if you've changed the rendering of the contour from the default line to another option.

Use the Remove button to delete selected contours. You may also press the Delete key on your keyboard.

If you delete a contour, you can't undo this action.

Use the show as drop-down to change the rendering of selected contours.

To render as a shell or a wireframe, you need to select at least three contours.

Use the points button to edit the shape of selected contours.

To modify the shape, click a point and drag it to the desired location.

Adjust point display: Useful to visualize the contour points better; changing the point size only applies to the display and will NOT affect the tracing data.

To edit a circle, click to select it then click Points: the center point of the circle and one of the outer ring points are highlighted.

• To move the contour, drag the center point.
• To resize, drag either point.