As a trained paper conservator it came as rather a shock when I was presented with the idea of conserving glass. I was first faced with the prospect during a short course at West Dean College, where I was told to fix a broken glass plate negative using an epoxy resin. Since then I’ve worked with glass on a regular basis, whether that be during framing artworks, or dealing with glass deterioration, which in turn then affects the framed artwork. Most recently during an internship with photographs conservator, Clara Waldthausen, I was asked to clean a large collection of deteriorating glass plate negatives. Invented in 1847, glass plate negatives produced extremely sharp images in comparison to the previously used negatives produced on paper. The glass plate process wasn’t very sensitive and took up to 15 minutes to make an exposure on the glass; consequently, it was used to mainly photograph buildings and landscapes. After 1878, there was an decrease in exposure time due to the advances of using gelatin, and as a result “instant photography” was born. A gelatin silver glass plate negative is composed of a glass plate coated with a gelatin coating that contains silver particles. Sadly, gelatin plates are often found in poor condition. The most frequently observed issues are broken or cracked glass, delamination of the gelatin emulsion, surface dirt, and glass deterioration. The collection that I was working with during my internship displayed all of the above problems. Below are some photographs of my efforts to preserve the large glass plate collection using methods such as, surface cleaning, repair and rehousing within PAT (Photographic Activity Test) quality materials. For more information please visit the University of Edinburgh’s conservation blog where I give details of preserving broken glass plates.
Samantha Cawson 
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