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Copyright of Journal of the American Institute for Conservation is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Analyses of two samples of the commercial platinum photographic paper 'Japine' revealed that this trade-name product was sold with a range of surface properties from matte to glossy. An in-depth examination of an unprocessed glossy Japine sample showed a chemically modified surface resulting from parchmentization by treatment with sulfuric acid. This treatment results in a thin film of amorphous cellulose on the printing surface, altering its visual appearance and wet strength. Photographers selected this paper due to its aesthetic qualities. However, such papers have never been characterized and are essentially unknown to modern-day scholars who may mistake them as prints with thin binder layers, such as albumen or gelatin. Indeed, the approach to conservation of these photographs may differ from one designed for a traditional platinum print. The parchmentized Japine paper was criticized for its tendency to crack, one characteristic that may have implications for its handling and conservation treatment today. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the American Institute for Conservation is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the late 1800s, pictorialist photographers favored a diversity of photographic techniques, including the gum dichromate process. Sometimes superimposed over other photographic images such as platinum and silver prints, the gum dichromate process utilizes a light-sensitive mixture of gum arabic, pigment, and a potassium dichromate solution hand-applied onto a sheet of paper and exposed to light while in direct contact with a negative. The definitive identification of this process has proven to be a challenge due to many variations and intermingling of techniques used by photographers of this period. This research began with a search through the historic literature, followed by the creation of test samples based on historic recipes, and the X-ray fluorescence analysis of these tests. The identification of pigments and the presence of chromium have been associated with the gum dichromate or other dichromated colloid processes in the past. Research results reveal that the presence of chromium may have more complex sources, requiring a more discriminating approach and a modified protocol for the identification of gum dichromate photographs. [ABSTRACT FROM AUTHOR]

The marble of the New York Public Library was found to be in a fairly good state of conservation except for the more exposed elements, such as quoins and the many delicately carved elements that decorate the building. This paper focuses on the treatment developed for areas that showed significant sugaring. For this purpose, laboratory examinations and analyses were carried out and preliminary tests were made with silicate ester-based consolidants. These, however, did not perform well in test studies and therefore an approach using inorganic materials was developed. The treatment consisted of spray application of an ammonium oxalate solution that reduced the intensive sugaring of the marble. To further protect these eroded surfaces, a shelter coat based on Type S hydrated dolomitic lime was also applied. This method is fully compatible with the marble substrate and follows the overriding principle of minimum intervention, as stated by the Venice Charter. [ABSTRACT FROM AUTHOR]