The separator item is a horizontal or vertical bar used to provide visual separation between items/commands in a group, toolbar, StatusBar or drop-down menus.

Adding Separator at Design-Time

The Ribbon Separator can be added at design-time using the Ribbon Group Floating Toolbar or RibbonGroup Items Collection Editor. Also, you can customize the look of the Ribbon Separator using the Ribbon Separator Floating ToolBar or by editing the properties in the Properties Window. For more information about floating toolbars, refer this topic. 

This image below shows the floating toolbar of Separator.

Adding Separator through Code

A separator can also be added to the C1Ribbon control through code using the RibbonSeparator class. This is depicted in the code snippet below:

' Add Separator ribbon item
Dim separatorItem As RibbonSeparator = New RibbonSeparator()
formatGroup.Items.Add(separatorItem)

// Add Separator ribbon item
RibbonSeparator separatorItem = new RibbonSeparator();
formatGroup.Items.Add(separatorItem);