To reproduce: - Set the font of the tool window: ((ToolTabStrip)this.toolWindow1.TabStrip).CaptionElement.Font = font1; - Make the tool window floating and then dock it again. - The font is not preserved. Workaround: Set the font in the DockStateChanged event.
The strip items are dynamically created and the windows type can be changed (floating, document, tool). This is why we cannot transfer any settings only the text. In this case the TabStripItemCreating event should be used for customizing the TabSrtipItem. Detailed information is available here: https://docs.telerik.com/devtools/winforms/dock/object-model/customizing-tabstrip-items