[.net] GDI+ Window Drawing Algorithm

I'm am trying to get the hang of drawing .NET controls (using C#) in the Paint event or the Paint override function of these controls. I'm not exactly fluent with the classes, functions, and techniques involved yet, but I can handle the basics. My question is this... When you are in the Form Designer, open up the Property window or any window for that matter. Now drag it around. The form disappears, except for the border which changes to a crosshatch pattern with inverted blending. That's exactly what I would like to do! I can do the transparent part. I just need the algorithm to draw that crosshatch pattern, and to do it with the inverted blending. I tried filling a rectangle using the HatchBrush with the Hatchstyle.Plaid style. Parts of that style are exactly what I need, but not the other parts. And then there is the whole inverted thing which I just don't know how to do with the tools you are given. Many thanks to a GDI+ pro who can guide me to the right solution.