The value of this property can be between 1/64 (0.015625) and 64.0, not inclusive. A value of 1.0 indicates that no zoom is applied to the control. The zoom feature performs optimally when the document contains TrueType fonts. When a font that is not TrueType is used within the document of the control, the RichTextBox.ZoomFactor property will use the nearest whole number value. You can use this property to enable the user of the System.Windows.Forms.RichTextBox control to zoom into sections of the documentation that are too small to view or to condense the view to enable more of the document to be viewed on screen.