Use the ToolTipFont property to assign a font for the control's tooltip. Use the ToolTipDelay and ToolTipPopDelay properties to define the time before showing a tooltip and the period of the time that tooltip remains visible if the mouse pointer is stationary within a control. The ToolTipWidth property specifies a value that indicates the width of the tooltip window, in pixels. Use the ToolTip property to assign a tooltip to a node. Use the ToolTipFont property to assign a font for the control's tooltip. You can use the <font> HTML element, in the tooltip's description to assign a different font for portions of text.