Latent Image keeping properties

Does anyone know how long an image will stay on an exposed but undeveloped wet plate? A museum curator nearby asked me if I could develop some of their exposed but un developed collection of glass plate negatives. The images are at least fifty years old.. I suggested that they not be processed. I have processed verichrome pan film that had a thirty year span between exposure and development. I was quite surprised that the image would keep so long. Are there commercial labs that process glass plate negatives? Assuming that they were shot by the same photographer and his methods had some consistency, They could develop one, and adjust development time, then do another. I told her I would look into it. This is the best place that I know of to get that info. thanks bk

With wet plate, my understanding is that it must never dry. So you have minutes total depending on the weather.
Dry plate could keep longer than film; many decades.
She may not know what type of plate she is dealing with. Have to inspect one under a safelight to see if it's handmade (uneven poor thickness, edges sometimes missing) or machine made looking.

I have wasted too much time, trying to process unknown film and dry glass plates, found in many used holders I have bought

Now I just remove the film and discard. I keep the glass plates as they are reusable after removing the emulsion

However I do collect and shoot ancient unused glass plates, any size

My hat to the left was shot on NOS 120 year old 5X7 dry glass plate

On a wet plate you generally have about 10 minutes to develop it. Much longer than that and it will dry out and the image is destroyed. It will simply dry up and the collodion curls off. Dry plates are different, more like film.


Kent in SD

Ask Jason Lane "Nodda Duma"

https://www.pictoriographica.com/