On the topic of dye bleach.......

Henry Wilhelm knows nothing about DB vs Chromogenic materials. The DB process is much more dangerous to use than any chromogenic prcess. DB materials were never possible to prepare with real camera speeds. It would take a family of shiftable dyes to make this possible. And finally, the grain in DB is at its maximum in medium to low density areas making the images you do get rather unpleasant. Kodak had a DB print process ready to go and its introduction date was 8 Dec 1941. It was called Azochrome.

PE