The painting conservators at the National Museum are responsible for around 6,500 paintings, ranging in time from the fifteenth century until the present day.
The collection consists mainly of Norwegian paintings on canvas, but also includes important European paintings, icons, and portrait miniatures from various eras, as well as an ever-expanding collection of modern and contemporary works.
The materials and techniques used in these works vary greatly. The collections include works where the artist has used binding agents such as oil, acryl, egg tempera, glue, PVA dispersions, wax, natural and synthetic resins, and house paint, but also foodstuffs such as gelatine. Painting surfaces range from primed canvases and wood panels to fibreboards, metals, and plastics.
Collections care and conservation
When taking care of such a diverse collection, there are a many different factors that have to be taken into consideration, but the aim will always be to choose conservation methods and materials that ensure the objects are preserved in the best possible condition over the longest possible stretch of time.
All materials age, whether in older or modern art. Such aging and degradation will typically manifest itself in the artwork changing its appearance, often over the course of many years, for example when a pigment fades or varnish yellows.
Every conservation process begins by documenting the condition of the work. This is followed by a thorough examination of the materials and techniques that have been used. This usually entails inspecting the painting’s surface with a stereo microscope and using lights of varying wavelengths, such as ultraviolet and infrared radiation and X-rays. Conservation may also involve taking small samples of the paint and studying the layering, pigments, binders, and surface material under a microscope with a high degree of magnification, often in the form of a cross-section. More advanced instruments make it possible today to identify the chemical elements and organic compounds that were originally used in the sample. Interviews with artists represent another key source of information about contemporary art.
As soon as there is sufficient information, the painting conservator can evaluate whether further treatment is necessary. Conservation measures may for example involve reinforcing the surface material, removing smudges and yellowed varnish, or securing loose painting.