Soft matter and art conservation. Rheoreversible gels and beyond

A form of soft matter, physical gels, has been exploited for many practical purposes for several centuries. During the last decade, several types of physical gels have been developed to clean surfaces for art conservation and restoration. A short history and an explanation of the structures and properties of these gels and recent modifications of them by the authors to allow ‘‘isothermal rheoreversibility’’ are described. Speculation about future developments and the factors that should be considered when formulating gels for art conservation and restoration is presented.