Compute Default Intervals: This option will calculate the minimum and maximum values of the grid being used and then set the regular and thick contour interval as well as the labeling interval and the distance between labels. Once default intervals have been calculated you can manually override any values.

Clear Overrides: This option will clear the regular and thick contour interval as well as the labeling interval and the distance between labels fields. If these 4 fields are left blank, then the default values will be used.

Color: The color of the normal contour line.

Interval: The interval to generate normal contour lines. For example, if you use a contour interval of 50, you will see a contour line every 50 meters (100, 150, 200 etc).

Width: The width of a normal contour line. It defaults to 0, which is the thinnest line width available, but the larger the number, the wider the contour line.

Color: The color of the thick contour line.

Interval: The interval to generate thick contour lines. For example, if you use a contour interval of 100, you will see a thick contour line every 100 meters (100, 200, 300 etc). This option is usually a multiple of the contour interval so that you can get a thick contour line every so often (every second line etc). If a thick contour interval overlaps a regular contour interval, the color and width of the thick contour line will be taken over the color and width of a regular contour line.

Width: The width of a thick contour line. It defaults to 5 but the larger the number, the wider the contour line.

Labeling Font: The font that the label will be produced in.

Labeling Size: The size of the label for the contour. If the size is defined as Variable Size, the label will appear to grow and shrink when zooming in and out on the Basemap. If the label is defined as Fixed Size, the label will remain relatively the same size when you are zooming in and out on the Basemap.

Labeling Interval: The interval that the label will be produced for. If you want a label on every contour line, then the labeling interval should match the contouring interval. An error message will appear if the labeling interval is not a multiple of the contouring interval.

Distance Between Labels: The distance on the same contour line that has to traverse before another contour label will be generated.

Number of Decimals: The number of decimal places that the contour labels will have.