I'm just wondering, because as I am scanning over 700 slides for a client that I'm considering the "This Side Towards Screen" that is printed on one side of the slide frame as the side that faces away from the viewer. But some of the slide images had writing in them and were obviously flipped. I can fix any of them that the client needs, but wanted to see if this is a common error that might have been done when a lab mounted slides. Did they ever pay attention to which way they were mounting the film? Or would some labs have been more acccurate with it than others?