Mitigation of recently formed fatty acid exudates using precision  mild heat transfer and IMAT mat. Sally Haley, Garlic, egg tempera on panel, 1980

 

We would also like to mention some new emerging applications of mild heat transfer, among these for the treatment of fatty acid exudates.  Although recommended treatment methodologies are still elusive, a conservative proposal is to reintroduce the saturated acids crystals that may be observed on unvarnished modern and contemporary egg tempera or oil paint surfaces, back into the paint film.  In this case, fatty acid exudates formed within a week following a high humidity event on the surface of this unvarnished egg tempera on hardboard by Sally Haley (1980s).  An initial attempted to remove the crystals mechanically was dissatisfactory, because of the change of the surface sheen. Instead, mild heat treatment was successfully used, heating sections to 45ºC for 10 minutes. The fatty acid exudates were reabsorbed by the paint film, leaving an intact surface.