MainForm with DockPanel (DocumentStyle = DockingMdi), couple of blank documents .
the document, now called SPECDOC which docks as Documt in the MainForm has an DockPanel it self (DocumentStyle = DockingSdi) to to be an Container for several DockContents. SPECDOC contains two dockcontens wich dock left and as document and contain a usercotrol now called SPECDOCCONTENT with several tablelayoutpanels and an gradientpanel as sample for custom OnPaint impl.
Effect: Resizing the MainForm does not repaint the SPECDOCCONTENT, it looks horrible!
Just resize the MainForm to the half of it max size an click the mximize button to see the atrifacts.