Posted By:
ramramThere must have been a real necessity to have the image as flat as possible. The photographer who assembled the original photograph mounted the CDV's on thin mounts (as opposed to the typically thicker mount of the time) and he also went to additional lengths to precisely clip several of the CDV's so that they didn't overlap (see link below from the original auction). I doubt that it would be all that important to have it this thin just for the purpose of framing the image. The only thing that comes to my mind is that the photographer wanted it as thin as possible so as to be able to photograph the composite image to produce a cabinet card from this original. The photographer would need the composite image as flat as possible so that he/she could produce a well focused image. Any variations in thickness would create areas slightly out of focus in his new image.
Rob M.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260011909333&indexURL=3&photoDisplayType=2#ebayphotohosting