Photographs

Some miscellaneous advice

Mechanised processing versus hand processing

Modern photographic processing systems cannot guarantee the same long-term stability as hand processing. However, mechanised processing is much cheaper and more convenient.

If the long-term stability of your colour prints is very important to you, it is wise to have them hand processed by a photographer, or to have them processed with a new batch of processing chemicals.

Cibachromes

Cibachromes are very stable, although they are very sensitive to moisture. If you want a very stable colour print, have a glossy Cibachrome print produced from a slide. Pearl Cibachromes are not as stable.

To laminate or not?

Lamination is sometimes promoted as a way to preserve your photographs, but there are problems associated with laminating photographs.

Once a photograph is laminated, it is virtually impossible to remove the lamination material without damaging the photograph and without using strong chemicals.

The process of lamination can damage the emulsion layer of the photograph; and over time the lamination material, with emulsion attached, will pull away from the paper base of the photograph. This damage is permanent.

Lamination may be suitable:

• if you have the negative and can print more copies of the photograph; and

• you want to protect the photograph in situations where it may get damaged or very dirty.

A reversible alternative is to place it in a Mylar sleeve.

Historic evidence accompanying photographs

Many photographs—particularly older photographs—may come into your collection in their original folder, in a frame or mounted on a card on which the photographer's name and address are printed.

Often these materials are dirty, deteriorating and not good quality. But they should not be discarded because they often provide valuable information about the photographs.

If the accompanying materials are in very poor condition, lightly brush them clean, then wrap, label and store them separately from the photographs.

From the mid-1850s to the early 1900s, cartes-de-visite and cabinet cards were very popular.

Cartes-de-visite are quite small; cabinet cards, which come in a range of sizes, are larger. Both are made up of photographs stuck down to card. These cards are often poor quality and brittle. Despite their poor quality, these cards should not be removed as they are an integral part of these items. A number of books on the history of photography give further details of these popular photographic formats.

Treatment of damaged photographs is not always simple. It is important when treating a photograph to be able to identify the process before determining the treatment to be applied. It is also important to know:

• what materials are likely to have been used. These can vary because many photographers experimented with materials and processes; and

• the particular sensitivities of these materials.

A note of warning about nitrate film stock

A number of collections contain examples of nitrate film, which was used for still film and movie film before the introduction of safety film.

Nitrate films are extremely dangerous. They consist of cellulose nitrate, a very unstable material.

As nitrate film degrades, it produces nitrogen oxide. Further degradation results in spontaneous combustion of the film; and because nitrogen oxide reactions produce oxidising agents, this reaction can occur without the presence of oxygen in the air. This means that degraded cellulose nitrate can burn under water or when smothered with fire-retarding foam or sand. Degraded cellulose nitrate is sticky and smelly.

The National Film and Sound Archive conducted a search for nitrate film in Australian collections in the mid-1990s. If you suspect you have cellulose nitrate in your collection, contact the National Film and Sound Archive, or a relevant State institution for information and advice.