In July 2009 the Getty Conservation Institute organized a weeklong colloquium at the Getty Center entitled "Cleaning of Acrylic Painted Surfaces: Research into Practice." The colloquium was a component of the GCI's Modern Paints project and the Science Workshops Series developed by GCI Education to connect conservation science with conservation practice. It is a first step toward developing an advanced training curriculum for the cleaning of acrylic painted surfaces.

The colloquium, conducted as a trial studio-based workshop in combination with presentations from instructors and discussion sessions, was led by Bronwyn Ormsby (Tate, London), Richard Wolbers (Winterthur Museum/University of Delaware Program in Art Conservation), Chris Stavroudis (independent conservator, Los Angeles), and Tiarna Doherty (J. Paul Getty Museum), with support from GCI scientists Tom Learner and Alan Phenix. The invited participants included practicing conservators, conservation scientists, and conservation educators from around the world.

The aims of the colloquium were: to explore the features of acrylic artists' paints which can make this material especially difficult to clean; to examine the role of minor additives in acrylic paints and their influence on the effects of cleaning systems; and to assimilate, review, and collectively interpret the scientific research conducted into cleaning these paints—particularly research on the fate of surfactant present in the original paint formulation.

Insights emerging from the weeklong program included recognition of the fundamental differences of acrylic paints in relation to traditional artists’ paint media, and of the crucial influence of ionic species (additives such as dispersing aids) and other water-soluble components (thickeners, surfactants) on the paint's sensitivity to water-based cleaning systems. In addition, reinforced throughout the event was the importance of precise control over the chemistry of aqueous cleaning formulations, especially in relation to pH and conductivity, and the need for balancing the conductivity of aqueous cleaning liquids with the conditions of the paint surface. The practical sessions of the colloquium allowed participants to have hands-on experience in measuring pH and conductivity of surfaces and to explore the influence of these parameters on cleaning performance.

For more information on the colloquium, visit the Science Workshop Series pages on the GCI Web site.