ashmolean
Using an endoscope to look inside a sculpture
Using an endoscope to look
inside a sculpture

Conservation Department

Investigation

Modern technology has provided the conservation profession with a range of sophisticated aids to assist in the task of preservation of our cultural heritage. To find out more about the objects in their care, conservators can use many different tools to investigate their condition, composition and history. This information is then used by the conservator when designing a treatment.

  • Raking and Transmitted Light

    WA1952.112. Transmitted light showing chain and laid lines of the sheet.
    WA1952.112. Transmitted light showing
    chain and laid lines of the sheet.
    Light shone at an angle across the surface of an object is called raking light, and the shadows that are cast show up any surface irregularities. When light is shone through an object from the back, it is called transmitted light. This method is used to reveal flaws in gems and watermarks in paper.

  • Infrared Light (IR)

    Infrared light is not visible to the naked eye but if a painted object is illuminated with IR, the paint layers appear more transparent than with normal (incandescent) light. This enables underdrawings, signatures, or inscriptions to be revealed. This new information can be recorded by photographing it with IR sensitive film.

  • Ultraviolet Light (UV)

    UV light is also invisible to the naked eye, but it can be useful since UV directed at certain substances, such as resins, will cause them to glow (fluoresce). This can reveal repairs, tears in canvasses under darkened varnishes, and overpainting (as old and new areas fluoresce differently). Even areas of paintings or manuscripts where pigments have faded or been lost can be enhanced. UV also has uses in the examination of wood, ceramics and other materials, but as it is damaging, it is only used for very short periods of time for investigative purposes.

  • Microscopy
    WA1941.107. x18 magnification detail of drying cracks in media.
    WA1941.107. x18 magnification detail of
    drying cracks in media.

    The microscope is the conservator's primary investigative tool, enabling them to observe details of an artefact. The microscope reveals dirt, damage (whether recent or ancient), cracks, and evidence of use and of original technology such as incised decoration and gilding. Also revealed on metal artefacts is the presence of mineralized organic remains of flesh, textile, or hair. Higher magnifications are used to reveal more information, such as the identification of the weave of a textile and the differences between types of pigments and media, fibres, wood and other materials.