Toronto. Photographs taken with any metal/glass/film based positive process have to be retaken or duplicated to make an added copies. Those of us who embraced the digital era have no need for such things – the digital process creates a file (usually RAW or jpeg) that can be duplicated endlessly with every copy identical unless purposely manipulated.
The Rothschild book (mine’s the 3rd edition, 3rd printing dated August 1977) goes back to the era of film and the many different gadgets that created duplicates, let you add titles, or even let you assemble selected positives as 35mm filmstrips to be shown by a projector (like the SVE line) that can accommodate film strips.
One of the earliest processes was the Daguerreotype which created a positive image on the surface of a silver-plated copper sheet. If you are a niche film enthusiast, you may still desire duplicate transparencies using the gadgets covered in Rothschild’s book.