Netherlands Institute for Conservation, Art and Science

NICAS Colloquium

14Feb2019 12:00 - 13:00


The next edition of the NICAS Colloquium takes place on Thursday, 14 February 2019, from 12:00 to 13:00 in Conference Room B of the Atelier Building (Hobbemastraat 22, Amsterdam).


The chair of this colloquium will be Thijs Hagendijk (Utrecht University).


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


Early eighteenth-century recipe for a smalt pigment

Paul van Laar

In a recipe for smalt pigment, the Dutch painter Simon Eikelenberg (1663-1738) describes how he grinds smalt with honey instead of water. The resulting pigment was the best smalt he had ever seen. Taking this claim as a point of departure, reconstructions were made based on Eikelenberg’s recipe to investigate the effect that honey has on the final pigment. TEM, inverted-light microscopy analysis, and Zetasizer size-measurements indicate that grinding the pigment with honey leads to a more effective separation of the smaller from the larger pigment particles during the washing. In addition, honey reduces the degree of aggregation of smalt particles during the washings of the pigment. TEM analysis further indicates that honey coatings surround the pigment particles after grinding, whereas acid-base titrations and Zetapotential measurements show that this coating is not only present during the washings, but that it also remains on the final pigment after the washings. This coating might play a role in preventing the leaching of components, such as potassium-ions, from the smalt to the surrounding medium, which has previously been suggested to be the main mechanism behind smalt discoloration properties.

Paul van Laar is a graduate from University College Utrecht and studies the role of honey in historical smalt preparation. He plans to enroll the Technical Art History programme of UvA in 2019.


Solvent-mediated extraction of fatty acids in bilayer oil paint models: a comparative analysis of solvent application methods

Lambert Baij

The 'impact' of solvent exposure on oil paintings and the differences between solvent application methods are longstanding topics in cleaning studies because solvent-swelling can lead to the extraction and displacement of soluble paint components and cause embrittlement of paint. We used the extraction of a saturated fatty acid (SFA) marker to quantify the impact of solvent cleaning. Three methods of solvent application were studied and compared: cotton swab, rigid gel and Evolon tissue (with different solvent loading). We conclude that both swab cleaning and squeezed Evolon tissue application result in comparable SFA extraction. The rigid gel and Evolon with controlled solvent-loading limit the amount of solvent application and SFA extraction. These results contribute to a better understanding of the impact of different methods of solvent application during cleaning or varnish removal on oil paintings and highlight important differences between these methods.

Lambert Baij was trained as an interdisciplinary researcher during his bachelor of natural and social sciences at the University of Amsterdam (UvA, Bèta Gamma). He is currently employed at the Rijksmuseum and the University of Amsterdam as a PhD candidate in chemistry supervised by prof. Piet Iedema and Katrien Keune.


Thursday, 14 February 2019


12:00 – 13:00 hrs


Conference Room B, Atelier Building
Hobbemastraat 22, Amsterdam

Published by  NICAS