In GTK+ a "drawable" is anything that you can "draw" to. This includes windows (GdkWindow) and offscreen buffers (GdkPixmap, GdkBitmap). Almost all the Gtk widgets handle their own drawing and need no help from you. Most of them have an associated GdkWindow which they use for this purpose; some, however, use their parent widget's window. So, trying to draw to a window of a widget is futile since it will all be erased once the widget is refreshed. If you want to draw your own little piece of art, use GtkDrawingArea widget which gives you a blank canvas to start from. Normally, you wouldn't draw to the GtkDrawingArea directly, because it doesn't have any "memory" -- as soon as another window covers it, the content of the underlying window is gone. What you have to do instead is draw to an offscreen pixmap (GdkPixmap) and then copy the contents of the pixmap to the window anytime it's exposed ("blit it").