on Asia-Pacific Forum for Library and Achives Management
Bangalore, India, UTC- June 1-30, 2004
Week 3: Conservation and Management of Photography
Hon. Lecturer in Non-Western History
University of Basel
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.
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,
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).
the speed at which chemical instability causes photographic
originals to change or fade
Basel we identify the following main threats to historical
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.
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).
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.
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.
the visual information on old photographs as comprehensively
as possible to a new and more permanent medium.
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
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.
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?