Microfading Tester International Discussion Group

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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Dear Noni,

While I don't have experience doing MFT on unfixed silver gelatin prints, one would need to be extremely careful with such objects due to their high sensitivity to light. One precaution would be to significantly reduce the light intensity during MFT - by either reducing power or using a neutral density filter - to slow the rate of color change; I recall Paul Whitmore recommending such an approach when testing pristine objects. Below are a few resources on silver gelatin prints, though you probably already know them all! (I also reached out to a few photo colleagues for resources and will share when I hear back from them.)

• XRF Identification of 20th Century Developer-Incorporated Stabilized Prints (2009)
• Conversation with Phil Chang about his 2012 Cache, Active exhibition
• Silver Gelatin, The Atlas of Analytical Signatures of Photographic Processes (2013)

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Vincent Laudato Beltran
Scientist, Getty Conservation Institute
Chair, MFT-IDG
vbeltran@getty.edu
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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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Dear Vincent and Katie,

Thank you for your response. I will forward your advice on to the student.

Thanks,

Noni

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Noni Zachri
Paper and Photographs Conservator
Grimwade Conservation Services
North Melbourne
Australia
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Original Message:
Sent: 09-08-2025 12:21
From: Katie Sanderson
Subject: Ageing of unfixed silver gelatin photographs

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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