Seminar-Workshop on Asia-Pacific Forum for Library and Achives Management Training
Bangalore, India, UTC- June 1-30, 2004

Week 3: Conservation and Management of Photography (4)

Paul Jenkins
Hon. Lecturer in Non-Western History
University of Basel
paul.jenkins@gmx.ch

4. Conservation

All photographic documents are – in the long run or maybe even sooner – chemically unstable. The kind of conservation churches and missions can pay for attempts to keep chemical and physical changes as close to zero as possible.

Two strategic lines need to be considered:

- reducing the speed at which chemical instability causes photographic originals to change or fade. This is the concern with the storage of originals and the restrictions in their use.

- transferring visual information as comprehensively as possible to a new and more permanent medium. This is the concern with the use of new, probably digital, storage media.

I concentrate here on photographic prints on a paper or cardboard backing. All other forms of historical photographic product – negatives, slides – present their own particular problems. (NB if you are lucky enough to have very early forms of photograph in your archive – daguerreotypes, ambrotypes, calotypes – treat them like the apple of your eye and get expert advice on their conservation.....and on how much they are worth).

Reducing the speed at which chemical instability causes photographic originals to change or fade

In Basel we identify the following main threats to historical photographc originals.

- bright light. Direct sublight is dangerous, of course, but we also avoid photoopying from photographic originals. If photocopying or scanning is done, an image should be subjected to this process once only, and not repeatedly.

- violent, sudden changes in air quality. (Even in Switzerland, if we take an original out of its air-conditioned store into a thundery/humid summer day, this means it goes from 15C to 30C and from 45% relative humidity to close to 100% in one short journey up a stairway). Rapid exposure to different air quality, as visible in these figures, may well alter the balance between the different chemical constituents of the photographic layer of a print, and the relationship between the photographic layer and the paper/card on which it has been deposited.

- friction, if the photographic layer on a paper print rubs against the back of the paper print before it in a file or album.

The best conservation method for photographic originals is to keep them in the dark under steady atmospheric conditions, and to place them in envelopes made of soft inert paper. (If you are dealing with photographs in an album then instead of envelopes you can use sheets of soft inert paper to lay between the pages of the album). Photographs should not be kept in air-tight conditions, in order to allow any gaseous products of chemical change to disperse, rather than concentrate themselves in the album. (In Basel we keep photographic originals at +/- 15C and +/-45% relative humidity. But it is worth discussing this point with your national or regional state archive, to see what standards they recommend in your particular environment).

These ideal conditions assume that an archive can build up a set of modern prints of its old photographs as “working copies”, so that originals are taken out of the archive only for restricted and very precisely defined purposes. Or they assume that originals can be transferred into a modern electronic medium, so that they can be consulted on screen. The basic point remains that the less old originals are handled, and the more they can be kept in stable circumstances, the slower they will decay.

Your customers should be prepared to pay prices which cover not only the prints which they order, but the production of “working copies”, prints and negatives, for the archive’s own future use.

Transferring the visual information on old photographs as comprehensively as possible to a new and more permanent medium.

There is no doubt that electronic storage can aid conservation. At the very least it enables archivists to insist that for all normal purposes images can and should be consulted on screen, thus reducing wear and tear on originals.

The more complicated question is whether an electrionic record can be regarded as a better form of permanent record than the original, subject as they both are to chemical decay.

Don’t forget (a) that electronic media also decay chemically, and that to make a digital archive truly permanent a very well-equipped and well-financed institution has to have a reliable system of renewing its electronic archive, and constantly updating its systems and software. Don’t forget (b) that to “read” an electronically-stored picture you need the appropriate machinery and software. How far will the machinery and software necessary to read the electronic photo files of today still be operational in 30 years time?

PJ Basel, 11.06.04