I have tested QGraphicsDropShadowEffect, but couldn't get it to do what I want.

Simply said (I hope), what I want to do is to add a soft black border around the white text in my qlabels, the white lines I paint with QPainter, and the white-bordered QPushButtons. This is because my gui is overlayed on video, and I want it to be clear both on black and white background. (And I need to use the white color).

Hope that explains it.