Author: Morgan T
Editors: Angela Pan, Jaylen Peng, Sumire Sumi, and Chiara Chen
Artist: Leo Li
It has become more common to see people combining elements of science and art in different ways, one example being art conservation. Art conservationists use chemical techniques and laboratory equipment, such as X-rays and microscopes, to protect and restore artworks. These artworks are not limited to ancient paintings but include different objects, paintings, paper, and photographs. The practice of restoring historical works has been around for centuries; however, the field is constantly evolving. In the past, art conservation focused more on restoring artworks to their original state, but by the 1940s, a more systematic approach to physical care had encouraged a more scientific basis for different treatments.
Modern conservators aim to study artworks in an environmentally friendly, non-invasive way, as old art can be very fragile. To eliminate traditional destructive techniques, conservators use infrared imaging to examine artworks and detect loss of paint and hidden details under the upper layer of the artwork. The nature and material used in the artworks also determine their restoration process. Using Raman microscopy, monochromatic light impinges on the material surface and is transmitted or reflected, with the measured frequency of the wavelength of light demonstrating the varnish characteristics. For the variety of varnishes, different organic solvents can be utilized to move the discolored layers; however, water is the most common solvent, which may be mixed with chelating agents, surfactants, or salt to control the pH.
Many Western and Eastern paintings in the medieval ages used lead white paint or lead hydroxy carbonate as an essential component. Production involved incorporating carbon dioxide and producing radioactive carbon-14 from burning plant sources. In this material, the relative rate of incorporation of carbon-14 is determined through high-resolution mass spectrometry measuring the difference in mass of the isotopes. However, this technique still needs to be more effective in measuring and precisely dating the material. Artists also tended to paint directly onto wet calcium hydroxide plaster, which reacts with atmospheric carbon dioxide to form calcite or calcium carbonate. For frescoes and plaster-based wall paintings, pollution, and humidity over time will cause the carbonate layer to break down, and salts within the walls will recrystallize, leading to deterioration of the painted surface. Baglioni's treatment injects calcium hydroxide nanoparticles. These tiny particles, of 10–100 nm, are dispersed in alcohol, which allows them to penetrate the frescoes and slowly reform the depleted calcite. Chemistry plays a crucial role in this process. To reverse chemical degradation, chemists would also reformulate original compositions.
Biological knowledge also contributes to the field. Many scientists and art conservationists would use harmless bacteria that produce enzymes to remove inorganic crusts and animal glues from frescoes. Synthetic polymers were used to consolidate and stabilize frescoes; however, scientists later discovered their presence could dramatically change the paintings’ surface properties. These polymers caused mechanical stresses and the crystallization of salts beneath the painting, leading to accelerated disintegration. Thus, evolving knowledge is essential to discover new ways of art preservation and restoration, as protecting ancient artworks is essential for the study of human civilizations. With the help of scientific knowledge, especially in chemistry and biology, conservators and art historians would better understand cultural objects without damaging these precious historical relics while also protecting themselves from harmful chemicals.
Citations:
National Museum of the Pacific War. (n.d.). Conservation vs Restoration: What is the
difference? [online] Metmuseum.org. (2021).
Wiki. (2019). Getting Started in Conservation Science. [online]
Chalkley, M. (2010). Art Restoration: The Fine Line Between Art and Science. [online] Yale
Scientific Magazine.
Rachel Brazil, Chemistry World (2014). Modern Chemistry Techniques Save Ancient Art.
[online] Scientific American.