Study and Conservation of a 19th Century Printed Silk Scarf from the Collection of the National Historical Museum of Greece

Aiming at an optimal gel-based methodology for the selective removal of stains on a 19th c. ink-printed silk scarf depicting the temple of Holy Trinity Church of Vienna, its history and preservation condition was identified with the help of optical microscopy, UVFC imaging, gloss and pH measurements, colorimetry, X-ray Fluorescence (XRF) and Fourier Transform Infrared (FTIR) spectroscopy. Emphasis was given on non-invasiveness and selectivity, for zeroing, or minimizing the effects from the cleaning methodology on the base material (silk) and the print (oil binder-based carbon black). Based on the analytical results, printed silk mock-ups were developed with polysaccharide stains, foxing spots and acrylic glue residues. These were artificially aged to simulate the pathology and condition of the printed scarf. The results of the gel-systems cleaning applications on the mock-ups led to the selection of the appropriate gel systems for the selective cleaning of the printed scarf: Αgar for polysaccharide deposits, Gellan gum-chelating factors (EDTA, DTPA) gel systems for foxing-metallic ions stains and Agar-enzyme lipase gel system for oxidized acrylic glue residues, were used. DEC-based PMMA and Nevek organogels, also used for the various tape backing detachment and adhesive removal from purpose made mock-ups. As enzyme, chelating factors, pH regulator (Trizma) and viscosity gel regulator (calcium acetate) were included in the gel formulations, their residues, after cleaning applications, were studied with infrared spectroscopy (ATR-FTIR) and ultraviolet induced visible fluorescence photography (UVFC).