A wxPaintDC must be constructed if an application wishes to paint on the
client area of a window from within an {\bf OnPaint} event.
This should normally be constructed as a temporary stack object; don't store
-a wxPaintDC object.
+a wxPaintDC object. If you have an OnPaint handler, you {\it must} create a wxPaintDC
+object within it even if you don't actually use it.
+
+Using wxPaintDC within OnPaint is important because it automatically
+sets the clipping area to the damaged area of the window. Attempts to draw
+outside this area do not appear.
To draw on a window from outside {\bf OnPaint}, construct a \helpref{wxClientDC}{wxclientdc} object.
\helpref{wxDC}{wxdc}
+\wxheading{Include files}
+
+<wx/dcclient.h>
+
\wxheading{See also}
\helpref{wxDC}{wxdc}, \helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxPaintDC}{wxpaintdc},\rtfsp