Netherlands Institute for Conservation, Art and Science

NICAS Colloquium

27Sept2018 12:00 - 13:00


The next edition of the NICAS Colloquium takes place on Thursday, 27 September 2018, from 12:00 to 13:00 in conference room B of the Atelier Building (Hobbemastraat 22, Amsterdam).


The chair of this colloquium will be Katrien Keune (Rijksmuseum).


The following presentations are scheduled for this edition of the NICAS Colloquium:

Garry Corthals

Towards ultra-fast and sensitive molecular assays

SAWN-MS is an ideal tool for molecular analysis of objects of art as it is non-destructive, rapid, involves minimally invasive
sampling and more sensitive than current MS-based methods. To perform SAWN, the sample is loaded onto piezoelectric
sampling chip where a fine mist is generated containing the analyte. Subsequent evaporation converts liquid-based molecular ions
to gas-phase ions destructively, from which spectra are obtained. In general we see a reduction in the sample size required and
little to no sample preparation compared to existing analytical procedures. Additionally, the total analysis time is often reduced
from several hours to several minutes, when compared to the existing MS-methods. I will introduce the instrumental operation
and configuration, experimental procedures and review several ultra-fast analyses ranging from human samples to bacteria, dyes
and original paint materials for art conservation/restoration studies, and forensics applications.

Garry Corthals is professor in Analytical Chemistry at the University of Amsterdam (UvA), and visiting professor at M4I of
Maastricht University. His group develops mass spectrometry based tools to analyse samples, ranging from patient to
environmental, forensic and art samples.

Tess Graafland

Investigating the potential of laser treatments for the removal of “bronze” overpaint on gilded picture frames

The collection of the Rijksmuseum contains many picture frames that have suffered from a treatment with brass-based paint. This
so called “bronze” overpaint is usually very generously applied on lacunas or abraded areas, covering a lot of the undamaged
surrounding gilding. On some occasions picture frames have been completely overpainted. The alloys in bronze paints have
oxidized in a few decades, resulting in dark green and brown patches or smears on the gilded surface. Removing these overpaints
would result in tremendous esthetic improvements for the frames. However, the removal of bronze overpaint from oil gilded
surfaces is often problematic. Current cleaning methods, using mechanical action or solvents, easily cause damage or loss of the
underlying gilding. Many solvents and solvents gels have either no cleaning effect or remove both bronze overpaint and oil gilding,
due to their often similar binding media. In collaboration with the Institute of Applied Physics (IFAC-CNR) in Florence a research
project was initiated, to investigate the potential of laser treatments for the removal of bronze overpaint on oil gilded surfaces.
Initial laser cleaning tests on frame fragments were performed with Nd:YAG (1064 nm) and Er:YAG (2940 nm) laser systems. A
preliminary study was focused on the interactions of these lasers with the bronze overpainted gilding, aiming to better understand
why a certain cleaning result is achieved and to optimize laser irradiation conditions.

Tess Graafland received her degree in furniture conservation at the University of Amsterdam. After an Annette de la Renta
fellowship in frames conservation at the Metropolitan Museum, she started as a junior frames conservator at the Rijksmuseum in

NICAS Colloquium

More information about the NICAS Colloquium can be found here.



Thursday, 27 September 2018


12:00 – 13:00 hrs


Conference Room B, Atelier Building
Hobbemastraat 22, Amsterdam

Published by  NICAS