Hello Noni,
I have some limited experience with measuring unfixed silver-based photographs and echo Vincent's point that doing MFT on an unfixed photograph will bring high risk and would definitely require a significant reduction of the light intensity. That said, I've seen unfixed photographs behave very differently under MFT conditions, so the rate of change can vary significantly depending on the object (https://monografias.editorial.upv.es/index.php/con_360/article/view/395/193 ).
If you have a reflectance spectrophotometer, you might want to consider real-time exposure experiments using your own samples even before trying the MFT. That would also be a useful way to evaluate the changes under actual exhibition conditions and could be a useful way to corroborate MFT results.
My best,
Katie
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Katie Sanderson
Conservator of Photographs
The Metropolitan Museum of Art
New York
United States
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Original Message:
Sent: 08-21-2025 18:56
From: Noni Zachri
Subject: Ageing of unfixed silver gelatin photographs
Hello everyone,
I have a student who is doing research on the ageing behaviour of unfixed silver gelatin photographs - a technique used by some contemporary artists. I wanted to know if anyone has experience doing MFT on these types of materials, or just general experience with how these materials age within gallery settings and if you could point us to some resources which may be helpful for this student's research?
Any advice is appreciated and thank you!
Noni
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Noni Zachri
Paper and Photographs Conservator
Grimwade Conservation Services
North Melbourne
Australia
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