Sunday, 7 March 2010

Tate - Evaluating the Effects of Cleaning Acrylic Paintings

Tate AXA Art Modern Paints Project (TAAMPP)

Evaluating the Effects of Cleaning Acrylic Paintings

The Tate AXA Art Modern Paints Project (TAAMPP) is a three year project funded by AXA Art Insurance, which enables a research team based at Tate to continue its evaluation of the effects of cleaning acrylic paintings.

Acrylic paints and primers have been widely used by artists since the early 1960s. They account for approximately 50% of paint sales over the last thirty years and they are the most common priming medium for modern canvases. It is estimated that acrylic materials are present in 30% of the Tate's collection of modern and contemporary paintings.

Although there is no sign that acrylic paints are any less stable than oil paints - in fact, they seem to be less likely to yellow and crack with age - they will require different conservation treatments from oils because their different composition.

Fig 1. Detail of fingerprints on an acrylic paint film.
© Tate 2006
Fig 2. Use of scanning electron microscope to show dirt particles embedded in an acrylic paint film.
© Tate 2006

The team at Tate is one of several research groups from museums or collaborating universities currently involved with assessing ways in which modern paint artworks can best be conserved in the future, in many cases before the signs of ageing become apparent. To date, appropriate conservation techniques have been limited and this research will lead the way in redressing this conservation concern.

More information on Tate's involvement in this larger network of researchers >

The project was launched on 1st April 2006 - full press release >

What are the main conservation issues about cleaning acrylic emulsion paints?

Acrylic paints tend to be:

■flexible and soft (at room temperature). This is excellent for preventing crack formation, but does mean that airborne dirt (and fingerprints) can slowly work their way into the paint film and end up being more difficult to remove.
■extremely vulnerable to many of the organic solvents commonly used in the conservation of oil paints. Acrylics would rapidly swell and start to dissolve if solvents such as alcohols or acetone were used. A new range of cleaning methods therefore needs to be established and tested.
■easily swollen by water and other aqueous cleaning systems, although this is not accompanied by the paint dissolving. However, the ramifications of this swelling need to be properly assessed.
■prone to surface changes on cleaning, in terms of burnishing and the development of uneven gloss and tide lines, which is particularly problematic in paintings that have large monochrome areas that can be difficult to clean evenly.
What do we know so far?

The principal findings from previous research are that acrylic paints appear to be:

■very stable (i.e. they do not change with age) compared to other paint types, such as oils and alkyds.
■responsive to changes in temperature and relative humidity (RH): they become brittle at low temperatures and soft and tacky at high temperatures; and they can swell considerably at high RH values.
■resistant to aqueous (i.e. water-based) cleaning solutions, apart from the removal of one of their minor components (a surfactant), which occurs readily from the paint's surface even if gently rubbed with a cotton wool swab. However, the removal of this component seems to have little effect on the paint's physical properties.
■totally resistant to cleaning with non-polar organic solvents, which do not remove surfactant from the paint surface or bulk film, and also have a negligible effect on physical properties.
■reasonably resistant to visual changes caused by surface cleaning, with some potential for minor changes in gloss, but this needs further investigation.
Specific aims of TAAMPP

These are to:

■assess the efficiency of surface cleaning treatment systems that are currently in use, using model paint samples covered in artificial dirt
■explore new / improved cleaning methods, with the aim of providing choice for conservators concerned about the extraction of material(s) from the paint film
■monitor case studies. Five acrylic emulsion paintings in the Tate collection will be surface cleaned and the effects of the treatments evaluated. This will help bridge the gap between evaluating model paints and actual works of art
■investigate the soiling (i.e. dirt deposition) of acrylic paint films, with a focus on the relationship between surface surfactant layers and soiling
■continue the investigation into the various physical, chemical and optical properties of acrylic paints that might be affected by cleaning and ageing.

Fig 3. Selection of yellow acrylic paint films after immersion in cleaning solutions and ready for testing.
Photograph Bronwyn Ormsby © Tate 2006
Fig 4. A paint film being tested in a Dynamic Mechanical Analyser, which can measure mechanical properties during immersion in liquids.
Photograph Bronwyn Ormsby © Tate 2006

The TAAMPP poster outlines much of this information. It was first presented at Modern Paints Uncovered (MPU) symposium, held at Tate Modern on 16-19 May 2006. This event, with more than 250 participants from over thirty-five countries in attendance, provided a unique forum for discussing the latest analytical, scientific, practical, and historical research in this area.
More information on the MPU symposium.

Case Studies

As part of TAAMPP, up to five acrylic paintings that are cleaned will be monitored closely. This aims to demonstrate the benefits to scientific research of constantly assessing the practical considerations that are faced by conservators. Case-studies will take research directly to practicing conservators.

The first painting to be assessed in this way will be Untitled 2/72 by the British artist Jeremy Moon (1934 -1973), which is being cleaned in preparation for a new display at Tate Britain in 2007, alongside other newly acquired works by Moon (Hoop-La and Untitled [72])


During the course of the Project, newsletters will be produced at six monthly intervals, outlining research progress and results.

Caring for Acrylics: Modern and Contemporary Paintings Tate and AXA Art [PDF format, 2.45MB]
Newsletter 1, October 2006 [PDF format, 40K]
Newsletter 2, May 2007 [PDF format, 60K]
Newsletter 3, January 2008 [PDF format, 226K]
Newsletter 4, September 2008 [PDF format, 1.2MB]
Newsletter 5, May 2009 [PDF format, 1.4MB]
Newsletter 6, November 2009 [PDF format, 1.5MB]
To view the newsletters you will need Adobe Reader

Research Summary

Tate AXA Art Modern Paints Project (TAAMPP): 2006-2009 Research summary [PDF format, 563KB]
Events / talks

■17 May 2006: Bronwyn Ormsby's presentation at Modern Paints Uncovered (MPU) symposium, Tate Modern, London
■19 May 2006: Poster presentation at MPU symposium, Tate Modern, London,
■14 June 2006: Public roundtable discussion at Art Basel Art fair, Basel
■16 June 2006: Reception at the American Institute for Conservation annual conference, Providence, USA
■19 October 2006 Roundtable discussion at Reina Sofia, Madrid
■26 October 2006: Roundtable discussion at Christie's, Paris
■16 January 2007: Presentation to the Decorative and Fine Art Society, The Hague
■17 January 2007: Presentations to Instituut Collectie Nederland, Amsterdam
■1 June 2007: Presentation to ICOM-CC Paintings Working Group Interim Meeting, British Museum, London
■28 June 2007: Presentation to BAPCR, London
■5 October 2007: Presentation to ICON, London
■18 October 2007: Presentation to AICCM National Conference, Brisbane
■23 November 2007: Presentation to University of Applied Arts, Vienna
■27 March 2008: Presentation to the Infra-red and Raman User's Group (IRUG), Vienna
■5 June 2008: Presentation to Instituut Collectie Nederland, Amsterdam
■25 July 2008: Presentation to Royal Institution, London
■24 September 2008: Presentation to ICOM-CC triennial conference, New Delhi
■21 October 2008: Presentations to University of Torino, Turin
■22 November 2008: Presentation to University of Perugia, Perugia
■6 February 2009: Presentation to Courtauld Institute of Art, London
■6 March 2009: Workshop at Courtauld Institute of Art, London
■13 March 2009: Presentation to Science and Engineering Week, London
■23 March 2009: Presentation to The Aristotle University of Thessaloniki, Thessaloniki, Greece
■24 March 2009: Presentation to The Aristotle University of Thessaloniki, Thessaloniki, Greece (E. Kampasakali)
■8 April 2009: Presentation to the Istituto Superiore per la conservazione ed il Restauro, Rome, Italy
■21 May 2009: Presentation to the AIC Annual Meeting, Los Angeles, USA (M. Keefe and A. Phenix DOW/GCI)
■25 June 2009: Presentation to the SF-IIC Paris (T. Learner (GCI)
■7-11 July 2009: Cleaning Acrylic Painted Surfaces (CAPS) workshop, Getty Conservation Institute, Los Angeles

Elina Kampasakali, AXA Art Research Fellow
Bronwyn Ormsby, Senior Conservation Scientist
Patricia Smithen, Lead Conservator, Paintings Conservation
Nicky White, Sponsorship Manager

Getty Conservation Institute
Tom Learner, Head of Contemporary Art Research

Benedetta Brandi, Marketing Co-Ordinator, AXA Art Italy, Milano
Frances Fogel, Communication and Liaison Co-ordinator, AXA Art UK, London
Thomas Wessel, Director of Art Expertise Management, AXA Art Group, Cologne (Head office)

Related Publications


■The Impact of Modern Paints (2000), by Jo Crook and Tom Learner
■Analysis of Modern Paints (2004), by Tom Learner
Online articles:

■Elizabeth Jablonski et al, 'Conservation Concerns for Acrylic Emulsion Paints: A Literature Review', Tate Papers (2004).
■Tom Learner, 'Modern Paints', Sackler NAS Colloquium, Scientific Examination of Art: Modern Techniques in Conservation and Analysis (2005).
■Mark Golden, 'Just Paint: Special Conservation Issue' (2006).
■Ormsby, B. et al. 'The Effects of Surface Cleaning on Acrylic Emulsion Paintings: A Preliminary Investigation' Tate Papers (2006).
Other articles:

■Ormsby, B., Smithen, P., and Learner, T. (2007). ‘Translating research into practice – evaluating the surface cleaning treatment of an acrylic emulsion painting by Jeremy Moon’. Contemporary Collections. Preprints of the Australian Institute for the Conservation of Cultural Materials (AICCM) National Conference, Brisbane, Australia, 2007, 97-109.
■Ormsby, B., Learner, T., Foster, G, Druzik, J., and Schilling, M. (2007) ‘Wet-cleaning Acrylic Emulsion Paint Films: An Evaluation of Physical, Chemical and Optical Changes.’ Modern Paints Uncovered, Tate Modern. Getty Conservation Institute, Los Angeles, 187-198.
■Ormsby, B., Foster, G., Learner, T., Ritchie, S., and Schilling, M. (2007). ‘Improved Controlled Temperature and Relative Humidity Dynamic Mechanical Analysis of Artists’ Acrylic Emulsion Paint Films: Part 1’ Journal of Thermal Analysis and Calorimetry, Vol. 90. 249-253.
■Ormsby, B., Foster, G., Learner, T., Ritchie, S., and Schilling, M. (2007). ‘Improved Controlled Relative Humidity Dynamic Mechanical Analysis of Artists’ Acrylic Emulsion Paints: Part 2. General Properties and Accelerated Ageing.’ Journal of Thermal Analysis and Calorimetry, Online First, February 2007.
■Ormsby, B., Learner, T., Schilling, M., Druzik, J., Khanjian, H., Carson, D., Foster, G., and Sloan, M. (2006). ‘The Effects of Surface Cleaning on Acrylic Emulsion Paintings – A Preliminary Investigation’. Oberflächenreinigung; Materialien und Methoden. VDR Schriftenreihe 2, Ed. Cornelia Weyer, Theiss Verlag, Stuttgart 2006, 135-149.

< Return to The Conservation of Modern Paints

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