New Insights into the Cleaning of Paintings

Extended Abstract—A Preliminary Study
into the Effects of Cleaning Polyvinyl
Acetate Paints
Ana Pereira, Maria João Melo, Peter Eaton,
Stephan Schäfer, and Tom Learner
INTRODUCTION
Ana Pereira and Maria João Melo, Departamento
de Conservação e Restauro and Requimte Departamento
de Química, Faculdade de Ciências e
Tecnologia, Universidade Nova de Lisboa, Quinta
da Torre, 2829-516 Caparica, Portugal. Peter
Eaton, Requimte, Departamento de Química e
Bioquímica, Faculdade de Ciências, Universidade
do Porto, Rua do Campo Alegre, 4169-007 Porto,
Portugal. Stephan Schäfer, Departamento de Conservação
e Restauro, Faculdade de Ciências e Tecnologia,
Universidade Nova de Lisboa, Quinta da
Torre, 2829-516 Caparica, Portugal. Tom Learner,
Contemporary Art Research, Getty Conservation
Institute, 1200 Getty Center Drive, Los Angeles,
California 90049- 1684, USA. Correspondence:
Ana Pereira, ana.pereira@campus.fct.unl.pt; Maria
João Melo, mjm@fct.unl.pt; Peter Eaton, peter
.eaton@fc.up.pt; Stephan Schäfer, schaef@fct.unl
.pt; Tom Learner, tlearner@getty.edu. Manuscript
received 19 November 2010; accepted 24 August
2012. Contributions to this paper by T. Learner
are Copyright © 2013 The J. Paul Getty Trust, all
rights reserved.
The effects of cleaning treatments on paintings made with synthetic paints are a
major concern for conservators of modern and contemporary art. Synthetic paints typically
include a complex mixture of additives that are likely to influence the paint’s response
to different treatment methods, and their high sensitivity to most organic solvents
narrows the choice of products that can be used. Knowledge gathered during cleaning
of traditional oil or egg tempera paintings can clearly not be directly correlated to contemporary
paintings. It is widely recognized by the conservation profession that further
research into the chemistry and properties of synthetic paints and their response to conservation
practice is therefore urgently needed.
This study presents the preliminary results on the effects that selected cleaning methods
have on test films of polyvinyl acetate (PVAc) paint and discusses implications for
cleaning paintings by Julião Sarmento (born 1948). He is one of the most prominent
contemporary Portuguese artists who made wide use of PVAc paints (Pereira et al., 2007).
In the 1990s he started a series of paintings, commonly called the White Paintings, that
require surface cleaning already because of a combination of their monochromatic white
backgrounds and affinity for dirt pickup.
MATERIALS AND METHODS
Samples of a PVAc emulsion paint containing titanium dioxide (rutile form) were
artificially aged using a xenon arc light source for 3250 hours. During this irradiation,
the mock- ups were exposed to dirt particles, i.e., atmospheric particulates. Commonly
used cleaning methods were subsequently tested: water, water and a nonionic surfactant
(Brij700S), and white spirit. Use of a soft eraser (Akapad White) was also examined to
reproduce a real case of cleaning a work by Sarmento. White spirit was included since
aliphatic mineral spirits are known to have a minimal effect on acrylic paints (Ormsby
and Learner, 2009), another main class of synthetic emulsion paints. Two samples were
used for each test, except for the white spirit.