Albumen prints and water

Airborne moisture is an unavoidable part of our world, and water is a critical part of the paper and photograph conservator's toolkit.  But research has shown that the principal modes of deterioration of albumen prints are significantly accelerated by water.

A large percentage of albumen prints show fading and yellowing, particularly characterized by loss of detail in highlight areas.  A 1982 study (1) investigated the possibility that inadequate processing explained this fading.  They prepared their own albumen prints, varying the length of final washing and the degree to which the fixer bath was exhausted; they then subjected the prints to 60 days of accelerated aging at 50 deg. C, at varying levels of humidity.  They found that inadequate washing did lead to greater fading and yellowing, but that effect largely disappeared with even a 1-minute wash in running water.  Further, they found that, while prints using thoroughly exhausted fixer showed greater yellowing and fading than those with fresher fixer, this was accompanied by a characteristic blackening of the image tone which is visible in some historic photographs, but is not typical.  The effects of the variations in processing were dwarfed by the yellowing and fading that occurred in all their samples when exposed to higher levels of humidity during accelerated aging.  This contrasts with the behavior of silver gelatin prints, which show comparative stability if properly processed.  Because the fading is accelerated even by moderately elevated levels of humidity, the authors recommend storing albumen prints in strictly controlled conditions, between 30% and 40% relative humidity and below 18 degrees C.

Paper conservators use humidity to "relax" paper, making it temporarily more flexible in order to flatten or re-shape it.  Heat and humidity in combination are particularly effective for flattening (just like ironing clothing), and this combination is used under some circumstances in paper and even photograph conservation.  (2)  Understanding the particular vulnerability of albumen prints should inspire caution to apply humidity sparingly to them, and never in combination with heat.  Conservators also use liquid water, both locally applied and by immersion, to remove surface dirt and to release water-soluble adhesives, as well as to wash damaging and discoloring substances out of paper.  These applications of water are extended to photographs on paper supports as well. (3)  To make an informed decision about the application of aqueous treatments to albumen prints, the effects of aqueous treatments on the albumen layer must be taken into account. 

In 1994, Paul Messier and Timothy Vitale (4) investigated the effects of aqueous surface and immersion treatments on albumen prints; they found that both surface and immersion treatment decreased gloss (suggesting disruption of the albumen layer), as well as increasing number and size of cracks in the albumen layer.  Immersion treatment also caused a small but measurable and permanent shrinkage of the prints after drying, and did not decrease yellowing.  In their 1999 study (5), Valerie Baas et. al. studied the effects of repeated immersion in four different solutions on newly-made albumen prints; all exhibited some damage, measured by change in gloss.  The least damaging of the baths they tried was a 50/50 mix of water and ethanol; an alkalized (pH 9) de-ionized water bath showed less gloss reduction than the plain de-ionized water bath, while a treatment with plain de-ionized water followed by an ethanol rinse (intended to result in quicker drying) showed more gloss reduction.  Paper expands less in a water-ethanol mix than in plain water, and proteinaceous layers expand more in an alkalized solution than in plain water; as the paper absorbs water and expands more readily than the albumen layer, either of those effects would reduce the strain on the albumen-paper complex.  The potential effects of an alkalized solution on the silver image compounds would have to be further investigated to determine if the alkalized solution would be on balance safer than a plain water wash; however, the Baas study does show that if overall aqueous treatment is necessary, an ethanol-water mixture is safer than pure water, and that a slow, controlled drying process is to be preferred over very rapid drying.



(1) Reilly, James M., et. al., "Image Deterioration in Albumen Photographic Prints",  Science & Technology in the Service of Conservation. IIC Congress, Washington DC. September 1982. p.61-64.  http://albumen.conservation-us.org/library/c20/reilly1982.html
(2) See section 5.3.6.2 of the draft American Institute for Conservation Photographic Materials Group catalog, http://www.conservation-wiki.com/wiki/PMG_Humidification,_Drying_and_Flattening ; note that this document is intended as abbreviated communications among professional conservators, and should not be construed as a stand-alone manual.
(3) As an example in the recent literature,  E. Roldão, L. Pavão, "The Conservation and Preservation of a Photographic Print: The 'Panoramic View of Constantinople'", e-conservation magazine, No. 14 (2010) pp. 70-79, http://www.e-conservationline.com/content/view/898  The inclusion of this reference is not intended as a criticism of their treatment choices.
(4) Messier, Paul and Vitale, Timothy, "Effects of Aqueous Treatment on Albumen Photographs",
Journal of the American Institute for Conservation, Vol. 33. 1994. pp. 257-78

(5)  Baas, Valerie, et. al, "The Effects of Four Different Wet Treatments on Albumen Photographs", Journal of the American Institute for Conservation. Summer, 1999, Volume 38, Number 2, pp 176-185