Treatment Documentation

Documenting each stage of a treatment is an important part of conservation work. Standards require both written and photographic records. With the Hogarth portraits, photographs were taken at various stages of treatment. William James appears here at an early stage of varnish removal, under normal light (left) and under ultraviolet light (right). Ultraviolet light is a useful tool because it causes some materials to fluoresce and can be useful in characterizing the materials present. For instance, natural resin varnishes (such as dammar or mastic) emit a hazy greenish-yellow fluorescence, such as here. This fluorescence is absent in the bottom left where the varnish has been removed.

Next: Varnish Removal
Previous Page Next Page Home Chapter Outline