Diagnosis of materials and effectiveness of Er:YAG Laser cleaning in a Borrassa’s Panel Painting (15th Century)

Laser research, Fine Arts Conservation, FTIR as applied to materials, Lichen research using a laser at 3 microns.  Current research the interaction of pulsed laser energy on painted surfaces, frescos.

"The Analysis and treatment of a panel painting from the North Carolina Museum of Art"

The deterioration of a 15th century Spanish panel painting by Lluis Borrassa (1365-1425) Christ before Pilot was, scientifically studied to devise a method to remove intractable restoration materials from the painting surface, that were particularly evident on the blue robes of the Christ figure, which appeared black. The painting was in need of cleaning: the dark old varnish obscured the design and colors of the painting.

A half century ago in an unsuccessful attempt to conceal damages to the painting, a restorer applied a pigmented varnish of a dark amber color to the surface. The varnish imparted an overall uniform tone to the painting and obscured the existing damages and paint losses.

The overall result of these treatments was that an intractable layer of material was left behind which needed to be carefully removed with a method not affecting the original painting layers.

To understand and to solve such problems, it was fundamental to identify the materials, which have been used by the artist and applied by restorers as well as to understand the oxidation pattern undergone by materials themselves.

A multi-analytical approach based on VIS-UV images, GC-MS, FT-IR, and SEM-EDX techniques has been employed, and herein presented, to identify original and added materials to the painting. This approach enabled us to understand and solve the problems associated with removing the intractable materials. The acquired new knowledge guided the conservators to choose and test some cleaning methods and finally resolved to adopt the Er:YAG laser cleaning method.

William P. Brown is Chief Conservator for the North Carolina Museum of Art (NCMA), Art Conservation Center where he is responsible for the long-term preservation of the collection and the development of preventive collections care strategies. He is a leader in the field of art preservation and a specialist in the treatment of Old Master Paintings.

He came to the NCMA in 1988 to complete his internship requirement for a M.A. and Certificate of Advanced Studies in Conservation, State University College at Buffalo, NY. He received his diploma in 1989 and continued with the NCMA first as assistant conservator then as associate conservator before his promotion to chief conservator in 2001. He is a Professional Associate, American Institute for Conservation of Historic and Artistic Works, and serves on the Paintings Committee of the International Council of Museums.

Adele DeCruz holds an MFA and Laura Professional from Dominican University, Villa Schifanoia, Florence, Italy and completed professional studies in the School of Historical Preservation at Columbia University. DeCruz is Visiting Professor at the University of Pisa, Italy. She has been a Samuel H. Kress Fellow, a consultant to the Vatican and the Opificio delle Pietre Dure, Florence, a Chief Conservator at the North Carolina Museum of Art and senior research Conservator at Nasher Museum of Art at Duke University. Her special expertise is the use of lasers to remove encrustations from the surface of art works, and she holds a patent on this method. She is Associate Adjunct Professor in the Departments of Chemistry and Biology, faculty member of the Fitzpatrick Institute for Photonics, Duke University, and Research Professor, Department of Physics at Union College.