The London Gels in Conservation Conference: An IntroductionWritten by Jodie Utter, Senior Conservator of Works on Paper, Amon Carter Museum of American Art.
Michelle Sullivan, “Rigid polysaccharide gels for paper conservation: a residue study”
This blog post is part of a series of observations about the London “Gels in Conservation” conference co-hosted by the Tate and IAP (International Academic Projects, Ltd). In mid-October, over the course of three days, some 41 authors presented research, techniques and ideas on gels in conservation. The talks were excellent, and I’ve focused on four that were notable for the wide range of materials treated and challenges faced. They ranged from coating/grime removal from a giant sequoia tree cross section, to dirt and varnish removal from Delacroix wall paintings, to removal of repairs from a fragile felt hat from a 18th century ship wreck, and an experiment comparing residues left behind by various gels on paper.
The fourth talk I wanted to highlight is Michelle Sullivan’s “Rigid polysaccharide gels for paper conservation: a residue study” -- of particular interest to me as a paper conservator. It was one of the few studies exploring quantitatively if residue is left behind by gels used in the treatment of works on paper. If so, did how does that residue impact the paper? To easily track residue on the paper samples, fluorescein dyes visible in UV light were added to the gels tested. The experiment used agarose, gellan gum and methyl cellulose gels in three different concentrations applied to three different papers for three different time periods. In addition, a few variables were added to mimic treatment, such as applying the gels through Japanese paper and clearing the gels using a damp swab. Besides surface examination, cross sections of the samples were also taken to see if the gels were penetrating the paper surface. The cross sections seemed to suggest that gellan gum was being absorbed into the paper. Sullivan found that all the gels tested left a residue, with gellan gum apparently leaving behind the most. She found that applying the gels through a Japanese paper barrier was the most effective method in minimizing residue. After oven aging for 21 days, the rag sample treated with gellan gum darkened slightly, while all the other samples did not. Sullivan proposed that the darkening might be related to the gelatin content of the rag test paper. She plans to expand her test variables and continue to build on this research. This feels like very important research and I eagerly await to results of the next phase of her work.
Residue Experiment set-up
This blog series is a result of receiving the FAIC Carolyn Horton grant to help me attend the conference. I would like to gratefully acknowledge the FAIC for helping make it possible for me to attend this important conference.