By default, the OverviewGridLines property has no effect until the Format property is specified and valid. The Visible property shows or hides the control's overview. The Format property specifies an expression to define the grid lines and labels between for the overview panel. The Color property specifies the line's color. The Style property defines the style of the line. The Width property specifies the line's width or size (1 by default). The Step property defines the step to show the grid lines. The Skip property specifies the number of grid lines to skip. The ChartGridLines property defines the configuration options to show the grid lines and labels between for the chart panel.