I was sitting in my "Survey of Western Art" class today, taking notes for all I was worth. We're on Late Gothic art (fascinating, I know). The lecturer put up some slides from a frescoed chapel in Italy to draw attention to the details in the paintings. The whole thing is done in frames, where the borders of each picture are decorated to look like actual frames, not just painted-on borders.
Well, in the frame of one picture were two portraits of saints painted inside two quatrafoils! I know it's a popular design in Europe, but it just made my day to see that.