Quote Originally Posted by BetterSense View Post
I went to an art exhibit this weekend where they had many digital prints made from what they said were original glass plate negatives shot during the 1930 discovery/robbing of King Tut's tomb. I don't know anything about glass plate negatives, but I had assumed that into the 1930s, they would be using nitro film. During what time period was silver-gelatin-on-glass in widespread use for commercial photography? When did film start to take over? I imagine that glass negatives can be printed just like film negatives, probably even easier because they are flat. But are there any other differences in technique compared to film? I suppose you need a special camera for glass as opposed to film negatives.
The glass negatives that Burton used were gelatin dry plate negatives. 'Glass negative' can also refer to wet plate collodion negatives (I believe Chris is referring to these when he says there are many who still pour and shoot glass plates.) As opposed to collodion photography, you don't need much in the way of special equipment for gelatin dry plates. You will need a plate holder, but they are easily made from old wooden film holders.

Enlarging for printing is identical as with film negatives, with the flatness benefit you pointed out. My 4x5 plates fit perfectly in my 4x5 negative carrier. I run into trouble with 5x7 because my holder is a glass carrier a half inch larger in both dimensions. I have set a 5x7 plate on the glass like I would a negative and the glass cover sheet. Works fine except for perhaps just a hint of light bounce.

There's more info on dry plate photography here:

Hope you give it a try!