Preserving photographs and microforms
The Archives holds more than 3 million photographic records, which occupy 7 per cent of our shelf space; almost all are 20th-century photographic materials. They are composite records and each format and type has its own preservation requirements.
These records have an image formed in a gelatin emulsion; black and white images are almost always formed by a metallic silver particle layer and colour images by dye layers. Photographic print images are on paper (occasionally plastic) bases, and negatives or positive transparencies have clear plastic bases.
Nitrate and acetate-based negatives are prone to deterioration of both the image and plastic support layers. This deterioration can be slowed significantly by storing the negatives at low temperature and relative humidity. The only other practical way to preserve the images and make them accessible is to digitise them.
Microform is the term used to cover a range of photographic media employed to copy documents. It includes microfilm, microfiche and aperture cards. Despite advances in digital technology, microforms are still a very popular record format as they allow compact storage of large amounts of information and enable the production of multiple copies. A master microfilm is usually black and white silver halide film made from original records. It is used to produce reference copies using less expensive and less archival dye-based processes. Microfilm readers are then used to view the reference copies.
Modern microfilms and other microforms are produced on polyester film, although older microfilm was manufactured with a cellulose acetate base. It therefore has the same deterioration characteristics and preservation needs as other photographic films. Typically, reference copies sustain mechanical damage with regular use. Providing good storage, appropriate packaging and correct handling of microforms will ensure they are preserved for the long term.
The Archives undertakes preservation treatments on photographic records to stabilise them. Basic photographic treatments include repackaging, flattening creases, repairing tears, dry cleaning and routine framing.
Complex treatments are labour intensive and usually restricted to records of special importance or with significant preservation problems. These treatments can include backing removals, linings, humidification and flattening, removing adhesive tapes, reducing stains, and specialised framing or display techniques.
We have a preservation digitisation program to copy photographic records that are deteriorating or are at risk. Each year approximately 30,000 images are digitised and made accessible through RecordSearch. Two recent series that have been digitised are the Immigration Photographic Archive (A12111), and photographic negatives and prints from the, Australian News and Information Bureau (A1200).
The Archives packages records in archival-quality materials that have passed the Photographic Activity Test (PAT) to prevent damage when they are stored and transported.
The Archives keeps records in environmentally controlled conditions on shelving appropriate for their size and format. The most at risk photographic and microform formats are kept at low temperatures. We even freeze some of our photographic material.
Example of an intensive repair
We selected this record for intensive treatment because of its significance and poor condition. Treatment included digitisation for access.
About the record
The 1901 record is a framed collection of photographs. It shows 71 (out of 76) members of the first Ministry of the Commonwealth of Australia and includes members of the House of Representatives.
Individual photographic portraits were mounted onto card and then stuck to a paper background. There is a handpainted title and text to identify the individual parliamentary members.
Research and existing damage
Scientific analysis was used to determine the structure of the photographs. X-ray fluorescence revealed that the photographs are platinum prints. Typically, this process produces image tones of soft greys, blues and black. The photo-sensitive chemicals absorbed directly by the top layers of the paper form the image and the lack of a binder gives a matt appearance. Another characteristic is the acidic deterioration of the support paper, while the platinum image remains virtually unaffected. The acidic nature of the images appears to have caused discolouration of the adjacent text panels. Some images were partially detached from the backing.
What we did
The frame was stabilised and individual images re-adhered. The original heavy glass cover sheet and deteriorated wooden stretcher (a secondary support frame for the picture) were removed. The glass was replaced with UV-filtering acrylic and the stretcher with archival board. We kept the original material as evidence of the initial structure.
Analysis and research were undertaken into the record's creation, construction and provenance, which will be useful for researchers and its preservation in the future. It has been digitised for access and returned to low-temperature storage.
The first Ministry of the Commonwealth of Australia and the members of the House of Representatives are depicted in this 1901 framed compilation of 71 photographs. The members' names and their states of origin are listed. (NAA: A7611, 1)