The Care of Stereo Photographs

Albumen Stereo Cards

Many albumen print cards survive in good condition to the present day, and the best of them still rival any modern print for contrast, definition, and tonal range.

However, as was observed already in the 1850s, the photographic image may be prone to fading, due to further chemical reactions taking place in the photographic layer.  This is mainly caused by the reaction of sulphur inherently present in the components of the image and/or residual active compounds left in the photographic substrate, following poor washing of the prints or inconsistent processing.

Here is an example of a badly faded albumen stereo card – the contrast is almost gone, and there is a general yellowing of the images. The dirty marks would be much less noticeable if the prints had survived in good condition.

Many albumen prints, now about 150 years old, show a cracked or fissured surface, caused by the shrinkage of the albumen, and highlights and whites have a tendency to yellow if the prints are kept in adverse conditions.

The cards should be kept cool and dry and away from direct sunlight.   The containers in which they are stored must be free of chemical emissions from glue polish, oils, etc, and only materials specifically produced for the archival care of photographs should be used.  The cards may be kept between sheets of archival paper, but for ease of viewing, and extra protection from careless fingers and the atmosphere, many collectors use archival plastic transparent sleeves.

Stereo Daguerreotypes

The best care of daguerreotypes is to interfere with them as little as possible – to keep them in a safe place, at a constant, low room temperature, and low humidity, and as far as possible, leave them alone !  Excessive handling gradually wears away the seals, and makes them more prone to tarnishing.  Vibration can cause the individual plates to move out of position.

This edge of a daguerreotype shows typical ‘early stages’ tarnish – oxidation of the silver plate, where the air has been getting in at the left hand side. The colours can be attractive, but if the plate is left for a long time exposed to the air, the image will eventually be completely obscured by the tarnish.

Once tarnish is present, it has always been tempting for collectors and dealers to attempt to restore the images.  This entails breaking the sealed daguerreotype slide apart, and immersing the plates in a reducing agent, such as thiourea.  The result can be quite dramatic, the plates being returned to mirror brightness, and the contrast of the images recovered to some extent.  But this may be achieved at a tragic cost.  Any colouring on the images is immediately lost in this process, and nobody can be sure what the long-term result of these ‘cleaning’ will be on the image will be.  Certainly there are cases recorded of images disappearing entirely at a later date due to cleaning. But even without these considerations, the cleaning of a sealed daguerreotype is regarded by most conservators as, in itself, a catastrophic and irreversible act.  The seal, once broken, can never be returned to its original state, the micro-environment between the plates and the glass is lost, along with a whole world of pollens, aerosols, and even small creatures of the 1850s … and effectively the daguerreotype, as an original piece, is destroyed.  Just to be perfectly clear, the best advice that can be given is – NO CLEANING OF A DAGUERREOTYPE SHOULD BE ATTEMPTED.