Netherlands Institute for Conservation, Art and Science

NICAS Colloquium

11Oct2018 12:00 - 13:00


The next edition of the NICAS Colloquium takes place on Thursday, 11 October 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 Rocio Garmendia (Rijksmuseum).


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

Klaas Jan van den Berg

Talens’ Tempera Paints - history, use, chemical aspects

Royal Talens is a leading artists’ paints manufacturer, founded in 1899. With Rembrandt oil paints among the best known range of products, Talens also produces other types of paints including tempera. A legendary paint of this type is ETA. Talens’ ETA is a type of casein/oil emulsion paint that was produced by Royal Talens in Apeldoorn from as early as 1933 till 1975. Although mainly in use as a rain-water resistant  decoration paint for example cinema advertisement, ETA paints were also popular among artists because of their versatility and their attractive matt finish. Artists from the COBRA artists group, among which Karel Appel, would use the paints in in conjunction with oil paints. Other types of tempera were based on resins mainly, such as copaiba balsam. Thanks to RCE’s collaborative agreement with Talens, new information has become available on the history of development of tempera paints in general, their formulations and application by artists. Paintings samples as well as historic tempera paints were analysed using a range of techniques. Analyt­ical challenges for its detection in art works, especially when mixed with oil paints, will be discussed.

Klaas Jan van den Berg is a senior conservation scientist at the Cultural Heritage Agency of the Netherlands. His current main focus is the study of formulations, techniques, material changes and surface cleaning in 20th-century oil paintings. Since 2016, he has been a part time full professor of Conservation Science (Painted Art) at the UvA.


Guus Verhaar

Investigating unstable glass in museum collections

The chemical deterioration of glass in museum collections is a large problem for conservators and curators. Objects of unstable composition typically show changes in appearance which may render an object unfit for display or even cause its complete disintegration. It has been estimated that up to 30% of glass objects in museum collections are susceptible to irreversible chemical deterioration. The identification of unstable glass objects is, therefore, essential for their preservation as it allows for the implementation of targeted conservation strategies. This presentation focuses on the early stages of glass deterioration. In particular, the presence and quantity of ions on glass surfaces, liberated from the glass during deterioration, has been studied. The detection of key ions in very low concentrations provides conservators with the potential to identify unstable glass objects in an early stage. The work presented was part of a recently completed PhD project.

Guus Verhaar is a post-doctoral researcher at the Rijksmuseum, Corning Museum of Glass and the University of Texas at Dallas. His main research interest is the chemical deterioration of glass in museum collections.

NICAS Colloquium

More information about the NICAS Colloquium can be found here.



Thursday, 11 October 2018


12:00 – 13:00 hrs


Conference Room B, Atelier Building
Hobbemastraat 22, Amsterdam

Published by  NICAS