Grabbing widget's background

[jpn]

Just an idea, not sure if it will work, but worth a try:
Try grabbing the desktop (QApplication::desktop()), and crop the grabbed image with the global coordinates of your child widget...

Thanks for the tip, but I would still have to hide the child widget during the grab.
I was hoping for something like a widget attribute or so, with which could I temporarily prevent the widget from drawing itself.