The Use of the Harris Matrix to Document the Layers Removed during the Cleaning of Painted Surfaces

Abstract

A significant difficulty in documenting cleaning processes for polychromed works is the overall recording of the stratigraphy of the structures involved, especially the non-original layers, which are composed of heterogeneous materials deposited on the surface. When these layers are removed, information about their stratigraphic configuration disappears. Archaeological stratigraphy provides interesting methods to document stratigraphic sequences. The Harris Matrix is a diagram that describes the chronological relationships between layers and other stratigraphic units. Adequately fitted, the Matrix can be used to record the removed layers and to contribute to a more accurate documentation, which will allow a future researcher to know what the state of the polychromed work was before the cleaning process.