The National Gallery is an Art Museum in Trafalgar Square in London founded in the 1842 years. All the painting’s collections are dating from the 13th to the 18th Century.
Some scientific researches about materials and technology of old paintings has been conduct at this National Gallery by scientists. Pigments, paints, varnishes and all the materials used for the conservation give very important informations on the chemical of the materials which were used in the works of these paintings. The researches use the analytical equipments as: IR microscopy, scanning electron microscopy, energy-dispertive X-Ray analysis, etc (1).
A video focused on microscopy to see the layers structure of painting (2) shows us, a man,, David Peggy investigates materials as varnishes, pain binder and pigment and a woman working also in the Gallery investigates about less structure paintings, identifies and analyzes the pigments. All these works allowed a good conservation of these paintings.
A picture is fascinating; The portrait of Alexander Mornauer. When the gallery bought it, the background of the picture was blue and through the time turns about a brownish color. So, the blue picture was examined by micro chemical test and chemists discovered this Prussian blue was a later addition.
During the examination of the picture, they shown different layers, this allows to have an uniform surface:
The panel painting construction is:
- Ground/preparation layer
- Drawing layer
- Paint layer
- Varnish which protects the picture.
To understand why the background of the picture have changed, they have taken a paint sample and look it at the microscope, which effectively shown the blue paint wasn’t the initial color but it was a brown color.
What is the event which makes this modification of color? Perhaps a chemical reaction between the different pigments, we don’t really know.
But, this show us a very interesting way in chemistry, using scientific knowledges and analytical techniques, a chemist can go into the history of the painting and finds the best conditions of painting conservation.
- 10 years ago: art analysis at the National Gallery, Chemistry World, 3 April 2014 (RSC)
- Video about analytical chemist at the National Gallery (RSC)