Removal of Pressure Sensitive Tapes From Vintage Silver Gelatin Prints Using Selected Gel-Based Systems: An Experimental Study

Historical photographs play a significant role as records, documenting the various stages of the history of Egypt and reflecting our identity and social, cultural, and religious values. Silver gelatin prints were the dominant positive printing processes in the 20th century. One of the most common forms of damage found among photographic collections is tears, which may result from improper handling and misuse, inappropriate storage, disasters, and other factors. In the past, tears were mended using pressure-sensitive tapes by amateurs and conservators. Over time, these tapes caused damage to the photographic surfaces since they oxidised, forming stains that are difficult and sometimes impossible to remove. Recently, many gel-based systems have been developed for use in the conservation of different cultural and historical materials, particularly paper artifacts. The aim of this research is to evaluate the efficacy of Klucel G and agar, as gel systems that are favoured by conservation specialists, in removing pressure-sensitive tapes from the surfaces of silver gelatin prints, as well as to study their effect on the photographs themselves. Organic solvents were added to the gel systems, and invaluable old photographs were used for this study. After treatment, samples were subjected to artificial ageing at a temperature of 80°C and 65% RH. Evaluation of the selected treatments was carried out through visual inspection, microscopic examination, colorimetric measurements, and attenuated total reflectance Fourier transform infrared spectroscopy. Results showed that both gel-based systems with mixed organic solvents gave great results compared to the conventional methods in terms of tape removal. However, colour change was detected in the case of agar gel-treated samples. Agarose gel may be a more proper option.