Took 4 hours of time for Lanchester's makeup and about 5 for Karloff. That left very little time for them to be in the same scene together. Poor ol Karloff was a Trooper. He started experiencing pretty bad back issues around then. By the time of his last few movies, he could hardly stand up and many scenes were of him sitting. In fact...One of our favorites when we'd see Summer Matinees, was "Die Monster Die". He was in a wheelchair for that movie.
