LASERS: A PRELIMINARY STUDY OF THEIR POTENTIAL FOR THE CLEANING AND UNCOVERING OF WALL PAINTINGS (COURTAULD INSTITUTE OF ART DISSERTATION)

Author(s): L Shekede

A pilot study sponsored by English Heritage was conducted which set out to observe and record the mechanisms by which radiation from three different laser types interacted both with coatings on polychromed surfaces and with the pigment layers themselves. To provide a framework for evaluating the potential of lasers for the removal of coatings in a conservation context, the basic principles governing laser operation were first outlined. The various means by which laser radiation acts upon surfaces were also described, and the principles and problems of establishing an approach to cleaning and uncovering were also briefly discussed. Three terracotta panels, each prepared using a different medium (fresco, tempera and oil) were coated with three types of material which are commonly found as surface contaminants (limewash, a wax-based, and a soot-based coating). A wide range of typical wall painting stratigraphies was thus provided on which to conduct laser trials. In order to differentiate between the effects of laser radiation on pigments, media and coating materials, two ceramic tiles were also prepared, one with a limited palette of pigments applied without binding media; the second with two types of medium (egg tempera and linseed oil) and one type of coating material (wax). [Long summary - see report].

Report Number:

68/1994

Series:

AML Reports (New Series)

Pages:

114

Keywords:

Conservation Methological Research Pigment