Use the ToolTipFont property to assign a font for the control's tooltip. The ToolTipPopDelay property specifies the period in ms of time the ToolTip remains visible if the mouse pointer is stationary within a control. Use the ToolTipWidth property to specify the width of the tooltip window. Use the CellToolTip property to specify the cell's tooltip. You can use the <font> HTML element, in the tooltip's description to assign a different font for portions of text.