New Insights into the Cleaning of Paintings

Extended Abstract—A New Documentation
System: Stratigraphic Units Recording
Sheets Applied to the Cleaning of a
Fifteenth-Century Painting
José Manuel Barros García and Eva Pérez Marín
INTRODUCTION
José Manuel Barros Garcia and Eva Pérez Marín,
Instituto Universitario de Restauración del
Patrimonio, Universidad Politécnica de Valencia,
Camino de Vera, s/n, 46022 Valencia, Spain.
Correspondence: José Manuel Barros Garcia,
jobargar@crbc.upv.es. Manuscript received 19
November 2010; accepted 24 August 2012.
At the beginning of the twenty- first century, a new direction began developing in
the stratigraphic study of painted surfaces thanks to the use of stratigraphic diagrams
and stratigraphic unit recording sheets. Harris’s (1989) work in the field of archaeology
brings important inspiration from what would appear to be a completely different field. It
is indeed still innovative for painting conservation despite having been introduced in the
study of ancient architecture some decades ago for the study of wall plasters.
The title of a paper by Harris (2006), “Archaeology and the Ethics of Scientific
Destruction,” perfectly highlights the importance of recording everything that will be
destroyed. This concept is vital in an archaeological excavation, just as it is in the cleaning
of a culturally significant object. The importance given nowadays to the nonoriginal
deposits present in an object’s surface is relatively recent. Traditionally, the restorer was
more worried about recovering the original work, and therefore, the nonoriginal layers
were nothing more than a troublesome barrier that hid the object and that had to be
destroyed at all costs. Although such deposits must be removed, today, it is considered of
key importance to document their existence in the most precise way possible. These deposits
do, in fact, constitute a valuable archive that retains important information about
how an object was produced, preserved, and displayed, about the chemical and physical
changes undergone by original and nonoriginal materials, and even about social context
or man’s way of thinking during a given period in history.
Each strata or layer (varnish, filler, overpaint, etc.) is called a stratigraphic unit (SU),
the smallest meaningful unit of the stratigraphic study, which has its own particular
physical characteristics. The strata are the positive units, and the losses, which must also
be recorded, are the negative units. A SU should be recorded according to three types of
main data: the description of its physical characteristics (e.g., color, texture, composition),
its location on the plan, and its relationships with the other units (where the SU is
situated within the stratigraphic sequence). All this information is gathered together on
a recording or data sheet, which thus becomes the central element of the documentation
system.