Conservation Trainee Helen has been working on various things during her period with us at Dorset History Centre. In this post, she takes a look at some interesting glass plate negatives…
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Dorset History Centre has recently acquired a new set of glass plate negatives, mainly of Thomas Hardy. As part of my placement here at DHC I have been tasked with cleaning and rehousing some of these plates. Glass plate negatives consist of a glass support and an emulsion layer of either collodion or gelatin. The emulsion is very sensitive to moisture so the cleaning of this side of the plate is only done with a soft dry brush to remove the loose surface dirt as much as possible. The glass side of the plate can be cleaned with a slightly damp cotton bud, but extra care has to be taken to ensure no moisture reaches the emulsion side of the plate.
While cleaning some of the smaller plates I noticed some red marks on the glass side of the plate on Hardy’s hat, which could well be some historical photo-editing! Because of the possibility of this having a historical reasoning behind it, the hat was avoided during cleaning so as not to remove the red marks.
Within the collection there are two larger glass plate negatives that need rehousing. One of these was unfortunately broken in 1974 when they were sent away to be printed by a publishing company. Of the collection sent away two were broken during processing and the company reimbursed the owner £11 in total!
Broken glass plates are very common in photographic collections and is the one of the main forms of damage these types of plates are subjected to. For these two plates we decided to create a sink mat to house them safely. This is particularly important for the broken plate as the shards have to be separated otherwise their edges can abrade against each other.
Though this portrait is broken, we can digitise and use modern photo-editing to piece it back together and allow us to see how it would have been originally. In the meantime we can be rest assured that the pieces are safe!