Cleaning concerns for acrylic emulsion paints

Abstract

Acrylic emulsion paints can contain significant quantities of surfactant, added to formulations at several points during the manufacturing process to perform functions such as latex emulsifiers, pigment dispersants, and wetting agents. In addition, as acrylic emulsion paints are highly responsive to temperature and relative humidity, the risk of dirt pick-up and retention increases with higher temperatures and relative humidity as the paint films soften even further. Most conservators use a combination of dry and wet cleaning methods to remove fingerprints and marks, although it can be difficult to avoid damaging or burnishing the soft paint surface. Microscopy has also been used to assess the relative swelling power of solvents on acrylic emulsion paints and any cross-sectional morphological changes resulting from simulated treatments. The accumulation of soiling causes changes in the optical properties of acrylic emulsion paint films such as the desaturation of colour and a reduction in surface gloss, which is often further reduced by the migration of surfactant.