I also watched the video from How It's Made - A hologram. I saw that on TV when it aired. How do I know? Because the second bath the the commintator said was bleach was not. It was either a stop bath or water rinse. The third bath which was yellowish was the bleach. But I must say I really liked his huge glass film sandwich plateholder. But he used no index matching fluid and he black taped the top and bottom of the film before sandwiching it in between the glass. To me that would cause the sandwich to be resting on the black tape and not the film.