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Science uncovers the hidden secrets of world-famous paintings

Issue date:
24 June 2010
Press release 
Engineering, Physical sciences
Photo of Ashok Roy

Ashok Roy with the EPSRC-funded gas-chromatography-mass-spectrometer

The hidden secrets of some of the world's most famous paintings have been revealed thanks to a partnership between EPSRC (Engineering and Physical Sciences Research Council) and the National Gallery.

Culminating in the first major exhibition of its kind in summer 2010, scientists at the Gallery have been using the latest equipment to shed new light on the history behind some of the Gallery's priceless works of art.

A state-of-the-art, EPSRC-funded gas-chromatography-mass-spectrometer (GC-MS) has helped specialists in the National Gallery's scientific department study the organic chemistry of old master paintings to understand how paintings were made and how they have changed over time. In painstaking investigations, the scientists used GC-MS to study the characterisation and composition of paint binding media, additions to paint media such as resins, and the composition of old varnishes.

The results of this work have raised complex questions of disputed authorship and authenticity, such as period copies or modern forgeries, and shed light on the original colour balance of paintings.

One example is The Virgin and Child with an Angel, which was originally attributed to the Renaissance painter-goldsmith Francesco Francia and dated about 1490. The painting's authenticity was queried in 1954 when another version appeared on the market and years of uncertainty ensued. Finally in 2009 a renewed campaign of scientific examination and comparative testing, including GC-MS testing on the paint media and varnish, proved beyond a shadow of doubt that the gallery's painting was indeed a fake that was painted in the 19th century.

As well as needing a meticulous approach, working on highly valuable paintings is also technically demanding.

Ashok Roy, Director of Science at the National Gallery explains: "Firstly only tiny quantities of material are available for analysis as samples, plus the organic content can be very complex. In addition, these materials have generally changed over time so that analysis may be of degraded materials the results of which have to be translated into assessments of the original chemical composition when the painting was first produced."

All these analyses are challenging in the sense that every picture presents new problems and subtle variations of chemistry and GC-MS is the ideal way of exploring these problems."

Roy describes uncovering something that no one else has seen for perhaps hundreds of years as "both fascinating and exhilarating".

Close Examination explores the pioneering work of the National Gallery's Scientific Department by presenting the varied and fascinating stories behind more than 40 paintings in the National Gallery's collection. The exhibition is arranged over six rooms, representing some of the major challenges faced by Gallery experts: Deception and Deceit; Transformations and Modifications; Mistakes; Secrets and Conundrums; Redemption and Recovery; and a special focus room relating to Botticelli. The exhibition features works by Raphael, Dürer, Gossaert, Rembrandt and others.

The partnership between the National Gallery and EPSRC has highlighted the contribution that science and scientists make in the world of art and shows the intellectual value that emerges when scientific and artistic traditions come together. EPSRC, together with Arts and Humanities Research Council, funds a Science and Heritage Programme which aims to increase knowledge and the resilience of our cultural heritage in the face of twenty first century challenges.

David Willetts, Minister for Universities and Science said: "People come from throughout the country and all over the globe to enjoy the National Gallery's sublime collection of paintings. This unique partnership with the UK's world-leading research base is prising open art's hidden secrets, illustrating the vital contribution science brings to our everyday lives."

Photo of Ashok Roy in the laboratory

Ashok Roy in the National Gallery’s scientific department

Notes for Editors

Gas-chromatography linked to mass-spectrometry is the core technique for these types of microanalyses of paint samples, and the techniques of analysis were developed first in the National Gallery laboratory, which remains a world leader in the study of the materials and techniques of Old Master paintings.

Paint binding media includes drying oils used in paintings, such as linseed oil, walnut oil and poppy seed oil. Analysis shows, for example, whether the oil was pre-treated by 'heat-bodying' (or thickening) before use by the painter. Added resins and other materials can also be identified and the state of degradation of the binder can be assessed. Paintings in other media, such as egg tempera can be identified, as well as complex combinations of media.

The National Gallery's Scientific Department was founded in 1934 and has become a world leader in the study of the materials and techniques of Western European paintings. Today, the department works ever more closely with curators and conservators to investigate the physical characteristics of works in the collection and to protect paintings for the future. Modern scientific methods, including infrared imaging, X-ray images, electron microscopy and mass spectrometry can provide fascinating insights into the materials used by artists, studio practice and the ways paintings can change over time.

A room-by-room description of the exhibition's six themes is available from the National Gallery site.


Close Examination: Fakes, Mistakes and Discoveries is curated by Marjorie E. Wieseman, Curator of Dutch Paintings at the National Gallery, and Ashok Roy, Director of Science at the National Gallery. The exhibition is supported by the Engineering and Physical Sciences Research Council (EPSRC).

Close Examination Research Online

From 30 June 2010, visitors to the exhibition site can explore detailed information on the major themes of the exhibition, including extensive research material and recent scientific discoveries.

Dates and Opening Hours - Admission Free

Press view: 29 June 2010, 10.30am - 1.30pm.
Open to public: 30 June 2010 - 12 September 2010. Daily 10am - 6pm, Friday until 9pm. Last admission 5.15pm (8.15pm Friday)

High resolution press images

Publicity images for Close Examination can be obtained from the National Gallery Press Office website. To obtain a username, contact the National Gallery Press Office on 020 7747 2865.

For images of the gas-chromatography-mass-spectrometer and Ashok Roy at work, contact:

EPSRC press office

Tel: +44 (0)1793 444404

Engineering and Physical Sciences Research Council (EPSRC)

EPSRC is the main UK government agency for funding research and training in engineering and the physical sciences, investing more than £850 million a year in a broad range of subjects - from mathematics to materials science, and from information technology to structural engineering.

EPSRC/AHRC Science and Heritage Programme

The Science and Heritage Programme aims to increase knowledge and the resilience of our cultural heritage in the face of twenty first century challenges. With joint funding by EPSRC and AHRC worth £8 million over five years, the Programme will build capacity through opportunities for collaboration among disciplines ranging from arts and humanities to science, engineering and technology; fund interdisciplinary research; and support training of young researchers.

Public information

The National Gallery, Trafalgar Square, London, WC2N 5DN
Tel: 020 7747 2885 or e-mail: National Gallery information


Thomas Almeroth-Williams
Tel: 020 7747 2512

Eloise Maxwell
020 7747 2420

EPSRC Press Office
Tel: 01793 444404