Hello.
I don't think that's possible, since every MDIChild has the same 'level' as the MDIClient Area.
Also overwriting the OnPaint Method of the MDIClient Area is impossible (at least I tried it hard, and couldn't figure out a way...except for disassemlbling everything using the reflector and piecing it back together).
Modifying or customizing the MDIClient Area is a pain in the a**...
Bobby