The scientific research department uses scientific techniques and instrumentation to carry out all aspects of its mission: investigation into the methods and materials of artists, scientific imaging, assessment of the suitability of materials used for exhibition and storage of art, and research and development of new materials for use in the conservation of works of art.

The Gallery's commitment to scientific research began in 1950 with the appointment of Dr. Robert L. Feller as technical advisor for conservation and curatorial activities. The department, which hired its first in-house scientist in 1976 and its first full-time scientist in 1984, now includes experts in the fields of chemistry, botany, conservation, and art history. The scientists work in collaboration with curators and conservators on topics related directly to the Gallery's collection, as well as on problems of general interest to the international conservation community. The department's fully equipped laboratory includes instrumentation for microscopy, chromatography, spectroscopy, and scientific imaging.

The results of the department's research are disseminated in publications and at national and international conferences, seminars, and symposia. The conservation community has adopted several new varnishes and conservation paints based directly on work done at the Gallery. Staff members collaborate with other conservation scientists and conservators in museums, conservation laboratories, and universities both nationally and internationally, and work with fellows, interns, and visiting scientists hosted each year by the department.

Research on the materials and techniques of works of art seeks to identify the materials used by artists and to understand the ways in which artists handled these materials. While this research often conjures up images of authentication or the exposure of forgeries, most research centers on two issues. One line of inquiry supports conservation treatments by distinguishing between the artist's original work and any alterations introduced by later restorers or by the aging process. Another area of research furthers art-historical studies by tracing the artist's decision-making process, revealed by changes to the work of art made by the artist during its creation or by choices of novel materials and techniques.

We utilize different regions of the electromatic spectrum such as visible light, infrared radiation, and X-rays to non-invasively map artists’ materials like pigments and paint binders across a work of art using custom imaging spectrometers. Such information is useful to conservators and art historians because it helps in understanding the working methods of a given artist. In addition to material maps, the collected images may also help visualize preparatory sketches or changes made by the artist during the painting process. The results of the work help to support the conservation treatment and technical study of the National Gallery of Art’s collection, provide new information for exhibitions, and develop new tools and procedures for the conservation community.

The museum provides a stable environment to display and store works of art. In addition to selecting the appropriate temperature, relative humidity, and lighting conditions, the materials for exhibiting and storing works of art must also be carefully considered. While a material might have perfect physical characteristics – cushioning, support, weather resistance, texture, color, etc. – it might cause harm to a delicate surface because of offgassing or transfer of reactive materials like acids. The lab is developing methods for analysis of the offgassing from plastics, metals, woods, paints and varnishes to insure that nothing damaging can interact with the surface of a work of art. Analysis of materials using gas and liquid chromatography provides the most rapid and diagnostic information, while less high-tech methods, such a microchemical testing or Oddy testing, can provide “thumbs up/thumbs down” answers and are available to museums without expensive equipment. All these methods are being refined in the lab, and the results shared with other cultural heritage institutions, so that we can both improve our testing methodologies and help other institutions find suitable materials for their collections.

Research into new materials and methods for conservation treatment serves to support conservators in their design of treatment strategies. Much of this research revolves around the use of gels in conservation practice. Removing components such as surface grime, deteriorated coatings, or embedded stains often requires the use of solvents—such as water, an organic solvent, or a mixture of the two—with or without additives. By using a gel, a liquid incorporated into a gel network can be delivered to the surface of an artwork in a controlled and gentle way. Research at the National Gallery of Art has explored the suitability of gels and other cleaning methods by studying material strategies to increase cleaning efficacy, limit unwanted residues, and prevent unintended surface changes to some of the more delicate surfaces found in artworks.

Research on conservation materials at the National Gallery of Art has also focused on coating materials, such as paints for retouching, coatings for the protection of outdoor bronzes, and varnishes for paintings. In this research, modern synthetic materials are tested for their use in conservation applications, often as replacements for traditional materials, which may be based on unstable natural products. Extensive use is being made of the expertise and materials available from the chemical industry. The materials are tested using accelerated aging methods. Stabilizing additives may be used to prolong the useful life of the materials. Conservators use an array of analytical methods to monitor changes during aging, after which time they judge the products for handling and appearance.