Photographic materials are sensitive to contaminants and variations in the climate. This means that proper archiving materials and the right climate conditions are particularly important to preserve photographs. The entire information of a photograph is contained in a thin layer. If this layer becomes damaged, the photo, positive or negative, is no longer legible. Consequently, when being handled, the image layer should only be touched with gloves.
We try to create the best possible conditions for the extensive photographic holdings of the Austrian National Library. Many old archive materials, such as envelopes containing wood pulp, need to be replaced in favour of ageing-resistant ones. The large holding of glass plate negatives is stored vertically in metal shelves. Endangered holdings, such as early film negatives, need to be controlled. Digital versions maintain the image information if the original changes. It is therefore important to digitalise endangered holdings before the information is lost.
We maintain the readability and reproducibility of photographs by stabilising the image layer and the substrate: on gelatine photographs we strengthen the gelatine layer; we glue behind tears in photograph paper and on cardboard; we touch up imperfections; we secure or glue glass plate negatives. We mount historically valuable photographs in passe-partouts.
In case of exhibitions, the aim is to find solutions to present light-sensitive photographs: on cardboard, in albums and sometimes for very large formats.
We needed to remove an almost two-metre long photograph, “Der Kaiser hält Cercle”, from a six millimetre-thick, heavily crinkled piece of cardboard in order to be able to present the photograph in a frame as part of the exhibition “The Eternal Emperor” in the State Hall.