A Danish phD thesis revealed that a common preservation method may cause more harm than good to artworks. The study showed that when an oil painting treated with the once-popular wax-resin lining is exposed to relative humidity over 60 percent there is a good chance that it will shrink, compressing the paint and causing it to flake off. The revelation was part of Cecil Krarup Andersen’s thesis, which was recently defended at the Royal Danish Academy of Fine Arts School of Conservation.
During the 20th century the “lining” technique was popular among conservators and used to protect well-known masterpieces including works by Rembrandt and Vincent van Gogh while traveling for loan exhibitions. For her thesis Lined canvas paintings: Mechanical properties and structural response to fluctuating relative humidity, Andersen studied the Danish national gallery's collection of Danish Golden Age paintings and examined the difference in moisture sensibility before and after wax-resin lining.
The wax-resin technique became popular during the 1960s but was obsolete by the 1970s since the method tended to darken paintings’ colors. However, the discovery of relative humidity’s effect on wax-resin lined canvases is a new finding. While the majority of museums maintain an approximate relative humidity of 50 percent, malfunctioning climate controls and flooding could leave some of the finest works in the canon of art in perilous danger.
