Remote and contactless infrared imaging techniques for stratigraphical investigations in paintings on canvas

Sofia Ceccarelli,Noemi Orazi,Massimiliano Ciaffi,Mario Ferri De Collibus,Francesco Petrucci,Massimo Francucci,Stefano Paoloni,Fulvio Mercuri,Massimiliano Guarneri,Ugo Zammit

doi:10.1007/s00340-021-07654-1

Abstract

In the analysis of complex stratigraphical structures like painted artefact, infrared (IR) techniques can provide precious information about elements hidden under superficial layers of the artwork, such as pictorial features and structural defects. This paper presents a novel complementary use of reflectographic and thermographic techniques for the survey of three baroque paintings, preserved at the Chigi Palace in Ariccia (Italy). First, the IR-ITR laser scanner prototype has been used for the preliminary and remote near-IR reflectographic survey of the areas where the canvas was located. The resulting map was then used for planning the thermographic and mid-IR reflectographic studies, focusing the analyses on the most interesting areas of one of the paintings, called “La Primavera”. The combination of the three imaging techniques revealed several details not visible by the naked eye, such as restored lacunas and pentimenti, demonstrating the validity and complementarity of the proposed combined methodologies.

Highlights

In the past, information on historical paintings concerning their realization procedures by the artists, as well as their preservation conditions, were gathered mainly from literary and historical sources
Such variations identified with the IR-ITR laser scanner consisted in pentimenti and adjustments in correspondence of some parts of the human figures and in the floral details, which have been subsequently analysed by the MWIR techniques
In the case of the La Primavera painting, useful and interesting results have been obtained by the novel multi-imaging approach combining three different infrared imaging techniques

Summary

Introduction

Information on historical paintings concerning their realization procedures by the artists, as well as their preservation conditions, were gathered mainly from literary and historical sources. 106 Page 2 of 13 size objects and/or requiring the placing of the artworks as close as possible to the acquisition apparatus, a practice that is not always possible. Another close-range technique is Infrared Thermography, recently employed as a non-destructive method in several fields, such as testing and evaluations in different kind of objects [18,19,20], investigation of the thermal transport properties of different materials [21,22,23,24,25] and specific applications on library and documentary artworks [26]

Methods

Results

Conclusion